/ Check-in [7769fb98]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Instead of a temporary b-tree, use a linked-list and merge-sort to sort records in main memory in vdbesort.c.
Downloads: Tarball | ZIP archive | SQL archive
Timelines: family | ancestors | descendants | both | merge-sort
Files: files | file ages | folders
SHA1:7769fb988d9be0f2d8129aaac19620ac88f9b4a6
User & Date: dan 2011-09-02 10:31:11
Context
2011-09-02
11:45
If all data being sorted fits in memory, avoid writing any data out to temporary files in vdbesort.c. check-in: 71075673 user: dan tags: merge-sort
10:31
Instead of a temporary b-tree, use a linked-list and merge-sort to sort records in main memory in vdbesort.c. check-in: 7769fb98 user: dan tags: merge-sort
2011-09-01
16:01
Use OP_SorterOpen instead of OP_OpenEphemeral to implement GROUP BY. check-in: ebf819aa user: drh tags: merge-sort
Changes
Hide Diffs Unified Diffs Ignore Whitespace Patch

Changes to src/btree.c.

1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759

  /* Only a BTREE_SINGLE database can be BTREE_UNORDERED */
  assert( (flags & BTREE_UNORDERED)==0 || (flags & BTREE_SINGLE)!=0 );

  /* A BTREE_SINGLE database is always a temporary and/or ephemeral */
  assert( (flags & BTREE_SINGLE)==0 || isTempDb );

  /* The BTREE_SORTER flag is only used if SQLITE_OMIT_MERGE_SORT is undef */
#ifdef SQLITE_OMIT_MERGE_SORT
  assert( (flags & BTREE_SORTER)==0 );
#endif

  /* BTREE_SORTER is always on a BTREE_SINGLE, BTREE_OMIT_JOURNAL */
  assert( (flags & BTREE_SORTER)==0 ||
          (flags & (BTREE_SINGLE|BTREE_OMIT_JOURNAL))
                                        ==(BTREE_SINGLE|BTREE_OMIT_JOURNAL) );

  if( db->flags & SQLITE_NoReadlock ){
    flags |= BTREE_NO_READLOCK;
  }
  if( isMemdb ){
    flags |= BTREE_MEMORY;
    flags &= ~BTREE_SORTER;
  }
  if( (vfsFlags & SQLITE_OPEN_MAIN_DB)!=0 && (isMemdb || isTempDb) ){
    vfsFlags = (vfsFlags & ~SQLITE_OPEN_MAIN_DB) | SQLITE_OPEN_TEMP_DB;
  }
  p = sqlite3MallocZero(sizeof(Btree));
  if( !p ){
    return SQLITE_NOMEM;







<
<
<
<
<
<
<
<
<
<





<







1730
1731
1732
1733
1734
1735
1736










1737
1738
1739
1740
1741

1742
1743
1744
1745
1746
1747
1748

  /* Only a BTREE_SINGLE database can be BTREE_UNORDERED */
  assert( (flags & BTREE_UNORDERED)==0 || (flags & BTREE_SINGLE)!=0 );

  /* A BTREE_SINGLE database is always a temporary and/or ephemeral */
  assert( (flags & BTREE_SINGLE)==0 || isTempDb );











  if( db->flags & SQLITE_NoReadlock ){
    flags |= BTREE_NO_READLOCK;
  }
  if( isMemdb ){
    flags |= BTREE_MEMORY;

  }
  if( (vfsFlags & SQLITE_OPEN_MAIN_DB)!=0 && (isMemdb || isTempDb) ){
    vfsFlags = (vfsFlags & ~SQLITE_OPEN_MAIN_DB) | SQLITE_OPEN_TEMP_DB;
  }
  p = sqlite3MallocZero(sizeof(Btree));
  if( !p ){
    return SQLITE_NOMEM;

Changes to src/btree.h.

57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
** pager.h.
*/
#define BTREE_OMIT_JOURNAL  1  /* Do not create or use a rollback journal */
#define BTREE_NO_READLOCK   2  /* Omit readlocks on readonly files */
#define BTREE_MEMORY        4  /* This is an in-memory DB */
#define BTREE_SINGLE        8  /* The file contains at most 1 b-tree */
#define BTREE_UNORDERED    16  /* Use of a hash implementation is OK */
#define BTREE_SORTER       32  /* Used as accumulator in external merge sort */

int sqlite3BtreeClose(Btree*);
int sqlite3BtreeSetCacheSize(Btree*,int);
int sqlite3BtreeSetSafetyLevel(Btree*,int,int,int);
int sqlite3BtreeSyncDisabled(Btree*);
int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);
int sqlite3BtreeGetPageSize(Btree*);







<







57
58
59
60
61
62
63

64
65
66
67
68
69
70
** pager.h.
*/
#define BTREE_OMIT_JOURNAL  1  /* Do not create or use a rollback journal */
#define BTREE_NO_READLOCK   2  /* Omit readlocks on readonly files */
#define BTREE_MEMORY        4  /* This is an in-memory DB */
#define BTREE_SINGLE        8  /* The file contains at most 1 b-tree */
#define BTREE_UNORDERED    16  /* Use of a hash implementation is OK */


int sqlite3BtreeClose(Btree*);
int sqlite3BtreeSetCacheSize(Btree*,int);
int sqlite3BtreeSetSafetyLevel(Btree*,int,int,int);
int sqlite3BtreeSyncDisabled(Btree*);
int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);
int sqlite3BtreeGetPageSize(Btree*);

Changes to src/build.c.

2322
2323
2324
2325
2326
2327
2328

2329
2330
2331
2332
2333
2334
2335
....
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381

2382
2383
2384
2385
2386
2387
2388
2389


2390







2391
2392

2393
2394
2395
2396
2397
2398
2399
2400
....
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
*/
static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
  Table *pTab = pIndex->pTable;  /* The table that is indexed */
  int iTab = pParse->nTab++;     /* Btree cursor used for pTab */
  int iIdx = pParse->nTab++;     /* Btree cursor used for pIndex */
  int iSorter = iTab;            /* Cursor opened by OpenSorter (if in use) */
  int addr1;                     /* Address of top of loop */

  int tnum;                      /* Root page of index */
  Vdbe *v;                       /* Generate code into this virtual machine */
  KeyInfo *pKey;                 /* KeyInfo for index */
  int regIdxKey;                 /* Registers containing the index key */
  int regRecord;                 /* Register holding assemblied index record */
  sqlite3 *db = pParse->db;      /* The database connection */
  int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
................................................................................
    sqlite3VdbeChangeP5(v, 1);
  }

  /* Open the sorter cursor if we are to use one. */
  if( bUseSorter ){
    iSorter = pParse->nTab++;
    sqlite3VdbeAddOp4(v, OP_OpenSorter, iSorter, 0, 0, (char*)pKey, P4_KEYINFO);
    sqlite3VdbeChangeP5(v, BTREE_SORTER);
  }

  /* Open the table. Loop through all rows of the table, inserting index
  ** records into the sorter. */
  sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
  addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);

  regRecord = sqlite3GetTempReg(pParse);
  regIdxKey = sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);

  if( bUseSorter ){
    sqlite3VdbeAddOp2(v, OP_IdxInsert, iSorter, regRecord);
    sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
    sqlite3VdbeJumpHere(v, addr1);
    addr1 = sqlite3VdbeAddOp2(v, OP_Sort, iSorter, 0);


    sqlite3VdbeAddOp2(v, OP_RowKey, iSorter, regRecord);







  }


  if( pIndex->onError!=OE_None ){
    const int regRowid = regIdxKey + pIndex->nColumn;
    const int j2 = sqlite3VdbeCurrentAddr(v) + 2;
    void * const pRegKey = SQLITE_INT_TO_PTR(regIdxKey);

    /* The registers accessed by the OP_IsUnique opcode were allocated
    ** using sqlite3GetTempRange() inside of the sqlite3GenerateIndexKey()
    ** call above. Just before that function was freed they were released
................................................................................
    sqlite3VdbeAddOp4(v, OP_IsUnique, iIdx, j2, regRowid, pRegKey, P4_INT32);
    sqlite3HaltConstraint(
        pParse, OE_Abort, "indexed columns are not unique", P4_STATIC);
  }
  sqlite3VdbeAddOp3(v, OP_IdxInsert, iIdx, regRecord, bUseSorter);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3VdbeAddOp2(v, OP_Next, iSorter, addr1+1);
  sqlite3VdbeJumpHere(v, addr1);

  sqlite3VdbeAddOp1(v, OP_Close, iTab);
  sqlite3VdbeAddOp1(v, OP_Close, iIdx);
  sqlite3VdbeAddOp1(v, OP_Close, iSorter);
}








>







 







<






>




|


|
>
>
|
>
>
>
>
>
>
>
|
<
>
|







 







|







2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
....
2369
2370
2371
2372
2373
2374
2375

2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401

2402
2403
2404
2405
2406
2407
2408
2409
2410
....
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
*/
static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
  Table *pTab = pIndex->pTable;  /* The table that is indexed */
  int iTab = pParse->nTab++;     /* Btree cursor used for pTab */
  int iIdx = pParse->nTab++;     /* Btree cursor used for pIndex */
  int iSorter = iTab;            /* Cursor opened by OpenSorter (if in use) */
  int addr1;                     /* Address of top of loop */
  int addr2;                     /* Address to jump to for next iteration */
  int tnum;                      /* Root page of index */
  Vdbe *v;                       /* Generate code into this virtual machine */
  KeyInfo *pKey;                 /* KeyInfo for index */
  int regIdxKey;                 /* Registers containing the index key */
  int regRecord;                 /* Register holding assemblied index record */
  sqlite3 *db = pParse->db;      /* The database connection */
  int iDb = sqlite3SchemaToIndex(db, pIndex->pSchema);
................................................................................
    sqlite3VdbeChangeP5(v, 1);
  }

  /* Open the sorter cursor if we are to use one. */
  if( bUseSorter ){
    iSorter = pParse->nTab++;
    sqlite3VdbeAddOp4(v, OP_OpenSorter, iSorter, 0, 0, (char*)pKey, P4_KEYINFO);

  }

  /* Open the table. Loop through all rows of the table, inserting index
  ** records into the sorter. */
  sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
  addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
  addr2 = addr1 + 1;
  regRecord = sqlite3GetTempReg(pParse);
  regIdxKey = sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);

  if( bUseSorter ){
    sqlite3VdbeAddOp2(v, OP_SorterInsert, iSorter, regRecord);
    sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
    sqlite3VdbeJumpHere(v, addr1);
    addr1 = sqlite3VdbeAddOp2(v, OP_SorterSort, iSorter, 0);
    if( pIndex->onError!=OE_None ){
      int j2 = sqlite3VdbeCurrentAddr(v) + 3;
      sqlite3VdbeAddOp2(v, OP_Goto, 0, j2);
      addr2 = sqlite3VdbeCurrentAddr(v);
      sqlite3VdbeAddOp3(v, OP_SorterCompare, iSorter, j2, regRecord);
      sqlite3HaltConstraint(
          pParse, OE_Abort, "indexed columns are not unique", P4_STATIC
      );
    }else{
      addr2 = sqlite3VdbeCurrentAddr(v);
    }

    sqlite3VdbeAddOp2(v, OP_SorterData, iSorter, regRecord);
  }else if( pIndex->onError!=OE_None ){
    const int regRowid = regIdxKey + pIndex->nColumn;
    const int j2 = sqlite3VdbeCurrentAddr(v) + 2;
    void * const pRegKey = SQLITE_INT_TO_PTR(regIdxKey);

    /* The registers accessed by the OP_IsUnique opcode were allocated
    ** using sqlite3GetTempRange() inside of the sqlite3GenerateIndexKey()
    ** call above. Just before that function was freed they were released
................................................................................
    sqlite3VdbeAddOp4(v, OP_IsUnique, iIdx, j2, regRowid, pRegKey, P4_INT32);
    sqlite3HaltConstraint(
        pParse, OE_Abort, "indexed columns are not unique", P4_STATIC);
  }
  sqlite3VdbeAddOp3(v, OP_IdxInsert, iIdx, regRecord, bUseSorter);
  sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
  sqlite3ReleaseTempReg(pParse, regRecord);
  sqlite3VdbeAddOp2(v, bUseSorter ? OP_SorterNext : OP_Next, iSorter, addr2);
  sqlite3VdbeJumpHere(v, addr1);

  sqlite3VdbeAddOp1(v, OP_Close, iTab);
  sqlite3VdbeAddOp1(v, OP_Close, iIdx);
  sqlite3VdbeAddOp1(v, OP_Close, iSorter);
}

Changes to src/expr.c.

2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
      AggInfo *pAggInfo = pExpr->pAggInfo;
      struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
      if( !pAggInfo->directMode ){
        assert( pCol->iMem>0 );
        inReg = pCol->iMem;
        break;
      }else if( pAggInfo->useSortingIdx ){
        sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdx,
                              pCol->iSorterColumn, target);
        break;
      }
      /* Otherwise, fall thru into the TK_COLUMN case */
    }
    case TK_COLUMN: {
      if( pExpr->iTable<0 ){







|







2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
      AggInfo *pAggInfo = pExpr->pAggInfo;
      struct AggInfo_col *pCol = &pAggInfo->aCol[pExpr->iAgg];
      if( !pAggInfo->directMode ){
        assert( pCol->iMem>0 );
        inReg = pCol->iMem;
        break;
      }else if( pAggInfo->useSortingIdx ){
        sqlite3VdbeAddOp3(v, OP_Column, pAggInfo->sortingIdxPTab,
                              pCol->iSorterColumn, target);
        break;
      }
      /* Otherwise, fall thru into the TK_COLUMN case */
    }
    case TK_COLUMN: {
      if( pExpr->iTable<0 ){

Changes to src/select.c.

4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
        }
        regRecord = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
        sqlite3VdbeAddOp2(v, OP_SorterInsert, sAggInfo.sortingIdx, regRecord);
        sqlite3ReleaseTempReg(pParse, regRecord);
        sqlite3ReleaseTempRange(pParse, regBase, nCol);
        sqlite3WhereEnd(pWInfo);
        sortPTab = pParse->nTab++;
        sortOut = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_OpenPseudo, sortPTab, sortOut, nCol);
        sqlite3VdbeAddOp2(v, OP_SorterSort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;
        sqlite3ExprCacheClear(pParse);
      }







|







4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
        }
        regRecord = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regRecord);
        sqlite3VdbeAddOp2(v, OP_SorterInsert, sAggInfo.sortingIdx, regRecord);
        sqlite3ReleaseTempReg(pParse, regRecord);
        sqlite3ReleaseTempRange(pParse, regBase, nCol);
        sqlite3WhereEnd(pWInfo);
        sAggInfo.sortingIdxPTab = sortPTab = pParse->nTab++;
        sortOut = sqlite3GetTempReg(pParse);
        sqlite3VdbeAddOp3(v, OP_OpenPseudo, sortPTab, sortOut, nCol);
        sqlite3VdbeAddOp2(v, OP_SorterSort, sAggInfo.sortingIdx, addrEnd);
        VdbeComment((v, "GROUP BY sort"));
        sAggInfo.useSortingIdx = 1;
        sqlite3ExprCacheClear(pParse);
      }

Changes to src/sqliteInt.h.

1546
1547
1548
1549
1550
1551
1552

1553
1554
1555
1556
1557
1558
1559
*/
struct AggInfo {
  u8 directMode;          /* Direct rendering mode means take data directly
                          ** from source tables rather than from accumulators */
  u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
                          ** than the source table */
  int sortingIdx;         /* Cursor number of the sorting index */

  ExprList *pGroupBy;     /* The group by clause */
  int nSortingColumn;     /* Number of columns in the sorting index */
  struct AggInfo_col {    /* For each column used in source tables */
    Table *pTab;             /* Source table */
    int iTable;              /* Cursor number of the source table */
    int iColumn;             /* Column number within the source table */
    int iSorterColumn;       /* Column number in the sorting index */







>







1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
*/
struct AggInfo {
  u8 directMode;          /* Direct rendering mode means take data directly
                          ** from source tables rather than from accumulators */
  u8 useSortingIdx;       /* In direct mode, reference the sorting index rather
                          ** than the source table */
  int sortingIdx;         /* Cursor number of the sorting index */
  int sortingIdxPTab;     /* Cursor number of pseudo-table */
  ExprList *pGroupBy;     /* The group by clause */
  int nSortingColumn;     /* Number of columns in the sorting index */
  struct AggInfo_col {    /* For each column used in source tables */
    Table *pTab;             /* Source table */
    int iTable;              /* Cursor number of the source table */
    int iColumn;             /* Column number within the source table */
    int iSorterColumn;       /* Column number in the sorting index */

Changes to src/vdbe.c.

3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
....
3211
3212
3213
3214
3215
3216
3217









3218
3219
3220






3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
....
4067
4068
4069
4070
4071
4072
4073


































4074
4075
4076
4077
4078
4079
4080
....
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108

4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
....
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
....
4417
4418
4419
4420
4421
4422
4423



4424
4425
4426
4427
4428
4429
4430
4431
4432
4433

4434
4435
4436
4437
4438
4439
4440
/* Opcode: OpenAutoindex P1 P2 * P4 *
**
** This opcode works the same as OP_OpenEphemeral.  It has a
** different name to distinguish its use.  Tables created using
** by this opcode will be used for automatically created transient
** indices in joins.
*/
/* Opcode: OpenSorter P1 P2 * P4 *
**
** This opcode works like OP_OpenEphemeral except that it opens
** a transient index that is specifically designed to sort large
** tables using an external merge-sort algorithm.
*/
case OP_OpenSorter: 
case OP_OpenAutoindex: 
case OP_SorterOpen:
case OP_OpenEphemeral: {
  VdbeCursor *pCx;
  static const int vfsFlags = 
      SQLITE_OPEN_READWRITE |
      SQLITE_OPEN_CREATE |
      SQLITE_OPEN_EXCLUSIVE |
      SQLITE_OPEN_DELETEONCLOSE |
      SQLITE_OPEN_TRANSIENT_DB;

  assert( pOp->p1>=0 );
  assert( (pOp->opcode==OP_OpenSorter)==((pOp->p5 & BTREE_SORTER)!=0) );
  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBt, 
                        BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5, vfsFlags);
  if( rc==SQLITE_OK ){
    rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
................................................................................
    }else{
      rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, pCx->pCursor);
      pCx->isTable = 1;
    }
  }
  pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
  pCx->isIndex = !pCx->isTable;









  pCx->isSorter = pOp->opcode==OP_SorterOpen;
#ifndef SQLITE_OMIT_MERGE_SORT
  if( rc==SQLITE_OK && pOp->opcode==OP_OpenSorter ){






    rc = sqlite3VdbeSorterInit(db, pCx);
  }
#endif
  break;
}

/* Opcode: OpenPseudo P1 P2 P3 * *
**
** Open a new cursor that points to a fake table that contains a single
** row of data.  The content of that one row in the content of memory
................................................................................
** This is used by trigger programs.
*/
case OP_ResetCount: {
  sqlite3VdbeSetChanges(db, p->nChange);
  p->nChange = 0;
  break;
}



































/* Opcode: RowData P1 P2 * * *
**
** Write into register P2 the complete row data for cursor P1.
** There is no interpretation of the data.  
** It is just copied onto the P2 register exactly as 
** it is found in the database file.
................................................................................
** There is no interpretation of the data.  
** The key is copied onto the P3 register exactly as 
** it is found in the database file.
**
** If the P1 cursor must be pointing to a valid row (not a NULL row)
** of a real table, not a pseudo-table.
*/
case OP_SorterData:
case OP_RowKey:
case OP_RowData: {
  VdbeCursor *pC;
  BtCursor *pCrsr;
  u32 n;
  i64 n64;

  pOut = &aMem[pOp->p2];
  memAboutToChange(p, pOut);

  /* Note that RowKey and RowData are really exactly the same instruction */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];

  assert( pC->isTable || pOp->opcode!=OP_RowData );
  assert( pC->isIndex || pOp->opcode==OP_RowData );
  assert( pC!=0 );
  assert( pC->nullRow==0 );
  assert( pC->pseudoTableReg==0 );
  assert( pC->isSorter==(pOp->opcode==OP_SorterData) );

  if( isSorter(pC) ){
    assert( pOp->opcode==OP_RowKey );
    rc = sqlite3VdbeSorterRowkey(pC, pOut);
    break;
  }

  assert( pC->pCursor!=0 );
  pCrsr = pC->pCursor;
  assert( sqlite3BtreeCursorIsValid(pCrsr) );

  /* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
  ** OP_Rewind/Op_Next with no intervening instructions that might invalidate
  ** the cursor.  Hence the following sqlite3VdbeCursorMoveto() call is always
................................................................................
  assert( pOp->p5<=ArraySize(p->aCounter) );
  pC = p->apCsr[pOp->p1];
  if( pC==0 ){
    break;  /* See ticket #2273 */
  }
  assert( pC->isSorter==(pOp->opcode==OP_SorterNext) );
  if( isSorter(pC) ){
    assert( pOp->opcode==OP_Next );
    rc = sqlite3VdbeSorterNext(db, pC, &res);
  }else{
    res = 1;
    assert( pC->deferredMoveto==0 );
    assert( pC->pCursor );
    assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
    assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );
................................................................................
  pIn2 = &aMem[pOp->p2];
  assert( pIn2->flags & MEM_Blob );
  pCrsr = pC->pCursor;
  if( ALWAYS(pCrsr!=0) ){
    assert( pC->isTable==0 );
    rc = ExpandBlob(pIn2);
    if( rc==SQLITE_OK ){



      nKey = pIn2->n;
      zKey = pIn2->z;
      rc = sqlite3VdbeSorterWrite(db, pC, nKey);
      if( rc==SQLITE_OK ){
        rc = sqlite3BtreeInsert(pCrsr, zKey, nKey, "", 0, 0, pOp->p3, 
            ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0)
        );
        assert( pC->deferredMoveto==0 );
      }
      pC->cacheStatus = CACHE_STALE;

    }
  }
  break;
}

/* Opcode: IdxDelete P1 P2 P3 * *
**







<
<
<
<
<
<
<

<










<







 







>
>
>
>
>
>
>
>
>
|
<
|
>
>
>
>
>
>
|
<
<







 







>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>







 







<













>







<
<
<
<
<
<







 







|







 







>
>
>
|
|
<
<


|

<
|
>







3158
3159
3160
3161
3162
3163
3164







3165

3166
3167
3168
3169
3170
3171
3172
3173
3174
3175

3176
3177
3178
3179
3180
3181
3182
....
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218

3219
3220
3221
3222
3223
3224
3225
3226


3227
3228
3229
3230
3231
3232
3233
....
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
....
4125
4126
4127
4128
4129
4130
4131

4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152






4153
4154
4155
4156
4157
4158
4159
....
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
....
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459


4460
4461
4462
4463

4464
4465
4466
4467
4468
4469
4470
4471
4472
/* Opcode: OpenAutoindex P1 P2 * P4 *
**
** This opcode works the same as OP_OpenEphemeral.  It has a
** different name to distinguish its use.  Tables created using
** by this opcode will be used for automatically created transient
** indices in joins.
*/







case OP_OpenAutoindex: 

case OP_OpenEphemeral: {
  VdbeCursor *pCx;
  static const int vfsFlags = 
      SQLITE_OPEN_READWRITE |
      SQLITE_OPEN_CREATE |
      SQLITE_OPEN_EXCLUSIVE |
      SQLITE_OPEN_DELETEONCLOSE |
      SQLITE_OPEN_TRANSIENT_DB;

  assert( pOp->p1>=0 );

  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
  if( pCx==0 ) goto no_mem;
  pCx->nullRow = 1;
  rc = sqlite3BtreeOpen(db->pVfs, 0, db, &pCx->pBt, 
                        BTREE_OMIT_JOURNAL | BTREE_SINGLE | pOp->p5, vfsFlags);
  if( rc==SQLITE_OK ){
    rc = sqlite3BtreeBeginTrans(pCx->pBt, 1);
................................................................................
    }else{
      rc = sqlite3BtreeCursor(pCx->pBt, MASTER_ROOT, 1, 0, pCx->pCursor);
      pCx->isTable = 1;
    }
  }
  pCx->isOrdered = (pOp->p5!=BTREE_UNORDERED);
  pCx->isIndex = !pCx->isTable;
  break;
}

/* Opcode: OpenSorter P1 P2 * P4 *
**
** This opcode works like OP_OpenEphemeral except that it opens
** a transient index that is specifically designed to sort large
** tables using an external merge-sort algorithm.
*/
case OP_SorterOpen:

case OP_OpenSorter: {
  VdbeCursor *pCx;
  pCx = allocateCursor(p, pOp->p1, pOp->p2, -1, 1);
  if( pCx==0 ) goto no_mem;
  pCx->pKeyInfo = pOp->p4.pKeyInfo;
  pCx->pKeyInfo->enc = ENC(p->db);
  pCx->isSorter = 1;
  rc = sqlite3VdbeSorterInit(db, pCx);


  break;
}

/* Opcode: OpenPseudo P1 P2 P3 * *
**
** Open a new cursor that points to a fake table that contains a single
** row of data.  The content of that one row in the content of memory
................................................................................
** This is used by trigger programs.
*/
case OP_ResetCount: {
  sqlite3VdbeSetChanges(db, p->nChange);
  p->nChange = 0;
  break;
}

/* Opcode: SorterCompare P1 P2 P3
**
** P1 is a sorter cursor. This instruction compares the record blob in 
** register P3 with the entry that the sorter cursor currently points to.
** If, excluding the rowid fields at the end, the two records are a match,
** fall through to the next instruction. Otherwise, jump to instruction P2.
*/
case OP_SorterCompare: {
  VdbeCursor *pC;
  int res;

  pC = p->apCsr[pOp->p1];
  assert( isSorter(pC) );
  pIn3 = &aMem[pOp->p3];
  rc = sqlite3VdbeSorterCompare(pC, pIn3, &res);
  if( res ){
    pc = pOp->p2-1;
  }
  break;
};

/* Opcode: SorterData P1 P2 * * *
**
** Write into register P2 the current sorter data for sorter cursor P1.
*/
case OP_SorterData: {
  VdbeCursor *pC;
  pOut = &aMem[pOp->p2];
  pC = p->apCsr[pOp->p1];
  assert( pC->isSorter );
  rc = sqlite3VdbeSorterRowkey(pC, pOut);
  break;
}

/* Opcode: RowData P1 P2 * * *
**
** Write into register P2 the complete row data for cursor P1.
** There is no interpretation of the data.  
** It is just copied onto the P2 register exactly as 
** it is found in the database file.
................................................................................
** There is no interpretation of the data.  
** The key is copied onto the P3 register exactly as 
** it is found in the database file.
**
** If the P1 cursor must be pointing to a valid row (not a NULL row)
** of a real table, not a pseudo-table.
*/

case OP_RowKey:
case OP_RowData: {
  VdbeCursor *pC;
  BtCursor *pCrsr;
  u32 n;
  i64 n64;

  pOut = &aMem[pOp->p2];
  memAboutToChange(p, pOut);

  /* Note that RowKey and RowData are really exactly the same instruction */
  assert( pOp->p1>=0 && pOp->p1<p->nCursor );
  pC = p->apCsr[pOp->p1];
  assert( pC->isSorter==0 );
  assert( pC->isTable || pOp->opcode!=OP_RowData );
  assert( pC->isIndex || pOp->opcode==OP_RowData );
  assert( pC!=0 );
  assert( pC->nullRow==0 );
  assert( pC->pseudoTableReg==0 );
  assert( pC->isSorter==(pOp->opcode==OP_SorterData) );







  assert( pC->pCursor!=0 );
  pCrsr = pC->pCursor;
  assert( sqlite3BtreeCursorIsValid(pCrsr) );

  /* The OP_RowKey and OP_RowData opcodes always follow OP_NotExists or
  ** OP_Rewind/Op_Next with no intervening instructions that might invalidate
  ** the cursor.  Hence the following sqlite3VdbeCursorMoveto() call is always
................................................................................
  assert( pOp->p5<=ArraySize(p->aCounter) );
  pC = p->apCsr[pOp->p1];
  if( pC==0 ){
    break;  /* See ticket #2273 */
  }
  assert( pC->isSorter==(pOp->opcode==OP_SorterNext) );
  if( isSorter(pC) ){
    assert( pOp->opcode==OP_SorterNext );
    rc = sqlite3VdbeSorterNext(db, pC, &res);
  }else{
    res = 1;
    assert( pC->deferredMoveto==0 );
    assert( pC->pCursor );
    assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
    assert( pOp->opcode!=OP_Prev || pOp->p4.xAdvance==sqlite3BtreePrevious );
................................................................................
  pIn2 = &aMem[pOp->p2];
  assert( pIn2->flags & MEM_Blob );
  pCrsr = pC->pCursor;
  if( ALWAYS(pCrsr!=0) ){
    assert( pC->isTable==0 );
    rc = ExpandBlob(pIn2);
    if( rc==SQLITE_OK ){
      if( isSorter(pC) ){
        rc = sqlite3VdbeSorterWrite(db, pC, pIn2);
      }else{
        nKey = pIn2->n;
        zKey = pIn2->z;


        rc = sqlite3BtreeInsert(pCrsr, zKey, nKey, "", 0, 0, pOp->p3, 
            ((pOp->p5 & OPFLAG_USESEEKRESULT) ? pC->seekResult : 0)
            );
        assert( pC->deferredMoveto==0 );

        pC->cacheStatus = CACHE_STALE;
      }
    }
  }
  break;
}

/* Opcode: IdxDelete P1 P2 P3 * *
**

Changes to src/vdbeInt.h.

399
400
401
402
403
404
405

406
407
408
409
410

411
412

413
414
415
416
417
418
419
#ifdef SQLITE_OMIT_MERGE_SORT
# define sqlite3VdbeSorterInit(Y,Z)      SQLITE_OK
# define sqlite3VdbeSorterWrite(X,Y,Z)   SQLITE_OK
# define sqlite3VdbeSorterClose(Y,Z)
# define sqlite3VdbeSorterRowkey(Y,Z)    SQLITE_OK
# define sqlite3VdbeSorterRewind(X,Y,Z)  SQLITE_OK
# define sqlite3VdbeSorterNext(X,Y,Z)    SQLITE_OK

#else
int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *);
int sqlite3VdbeSorterWrite(sqlite3 *, VdbeCursor *, int);
void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
int sqlite3VdbeSorterRowkey(VdbeCursor *, Mem *);

int sqlite3VdbeSorterRewind(sqlite3 *, VdbeCursor *, int *);
int sqlite3VdbeSorterNext(sqlite3 *, VdbeCursor *, int *);

#endif

#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
  void sqlite3VdbeEnter(Vdbe*);
  void sqlite3VdbeLeave(Vdbe*);
#else
# define sqlite3VdbeEnter(X)







>


<


>

|
>







399
400
401
402
403
404
405
406
407
408

409
410
411
412
413
414
415
416
417
418
419
420
421
#ifdef SQLITE_OMIT_MERGE_SORT
# define sqlite3VdbeSorterInit(Y,Z)      SQLITE_OK
# define sqlite3VdbeSorterWrite(X,Y,Z)   SQLITE_OK
# define sqlite3VdbeSorterClose(Y,Z)
# define sqlite3VdbeSorterRowkey(Y,Z)    SQLITE_OK
# define sqlite3VdbeSorterRewind(X,Y,Z)  SQLITE_OK
# define sqlite3VdbeSorterNext(X,Y,Z)    SQLITE_OK
# define sqlite3VdbeSorterCompare(X,Y,Z) SQLITE_OK
#else
int sqlite3VdbeSorterInit(sqlite3 *, VdbeCursor *);

void sqlite3VdbeSorterClose(sqlite3 *, VdbeCursor *);
int sqlite3VdbeSorterRowkey(VdbeCursor *, Mem *);
int sqlite3VdbeSorterNext(sqlite3 *, VdbeCursor *, int *);
int sqlite3VdbeSorterRewind(sqlite3 *, VdbeCursor *, int *);
int sqlite3VdbeSorterWrite(sqlite3 *, VdbeCursor *, Mem *);
int sqlite3VdbeSorterCompare(VdbeCursor *, Mem *, int *);
#endif

#if !defined(SQLITE_OMIT_SHARED_CACHE) && SQLITE_THREADSAFE>0
  void sqlite3VdbeEnter(Vdbe*);
  void sqlite3VdbeLeave(Vdbe*);
#else
# define sqlite3VdbeEnter(X)

Changes to src/vdbesort.c.

17
18
19
20
21
22
23

24
25
26
27
28
29
30
..
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103



104
105
106
107
108
109
110
...
112
113
114
115
116
117
118











119
120
121
122
123
124
125
...
271
272
273
274
275
276
277












































278
279
280
281
282
283
284
...
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332


333
334

335




















336
337
338
339
340
341
342
...
347
348
349
350
351
352
353

354
355
356
357
358
359
360
...
366
367
368
369
370
371
372














373




































374




































































375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391

392
393
394
395


396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420

421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443


444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
...
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
...
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711


























712

#include "sqliteInt.h"
#include "vdbeInt.h"

#ifndef SQLITE_OMIT_MERGE_SORT

typedef struct VdbeSorterIter VdbeSorterIter;


/*
** NOTES ON DATA STRUCTURE USED FOR N-WAY MERGES:
**
** As keys are added to the sorter, they are written to disk in a series
** of sorted packed-memory-arrays (PMAs). The size of each PMA is roughly
** the same as the cache-size allowed for temporary databases. In order
................................................................................
**     aTree[] = { X, 0   0, 6    0, 3, 5, 6 }
**
** In other words, each time we advance to the next sorter element, log2(N)
** key comparison operations are required, where N is the number of segments
** being merged (rounded up to the next power of 2).
*/
struct VdbeSorter {
  int nWorking;                   /* Start a new b-tree after this many pages */
  int nBtree;                     /* Current size of b-tree contents as PMA */
  int nTree;                      /* Used size of aTree/aIter (power of 2) */
  VdbeSorterIter *aIter;          /* Array of iterators to merge */
  int *aTree;                     /* Current state of incremental merge */
  i64 iWriteOff;                  /* Current write offset within file pTemp1 */
  i64 iReadOff;                   /* Current read offset within file pTemp1 */
  sqlite3_file *pTemp1;           /* PMA file 1 */
  int nPMA;                       /* Number of PMAs stored in pTemp1 */



};

/*
** The following type is an iterator for a PMA. It caches the current key in 
** variables nKey/aKey. If the iterator is at EOF, pFile==0.
*/
struct VdbeSorterIter {
................................................................................
  i64 iEof;                       /* 1 byte past EOF for this iterator */
  sqlite3_file *pFile;            /* File iterator is reading from */
  int nAlloc;                     /* Bytes of space at aAlloc */
  u8 *aAlloc;                     /* Allocated space */
  int nKey;                       /* Number of bytes in key */
  u8 *aKey;                       /* Pointer to current key */
};












/* Minimum allowable value for the VdbeSorter.nWorking variable */
#define SORTER_MIN_WORKING 10

/* Maximum number of segments to merge in a single pass. */
#define SORTER_MAX_MERGE_COUNT 16

................................................................................
  }
  if( rc==SQLITE_OK ){
    rc = vdbeSorterIterNext(db, pIter);
  }
  return rc;
}













































/*
** This function is called to compare two iterator keys when merging 
** multiple b-tree segments. Parameter iOut is the index of the aTree[] 
** value to recalculate.
*/
static int vdbeSorterDoCompare(VdbeCursor *pCsr, int iOut){
  VdbeSorter *pSorter = pCsr->pSorter;
................................................................................
  p2 = &pSorter->aIter[i2];

  if( p1->pFile==0 ){
    iRes = i2;
  }else if( p2->pFile==0 ){
    iRes = i1;
  }else{
    char aSpace[150];
    UnpackedRecord *r1;

    r1 = sqlite3VdbeRecordUnpack(
        pCsr->pKeyInfo, p1->nKey, p1->aKey, aSpace, sizeof(aSpace)
    );
    if( r1==0 ) return SQLITE_NOMEM;

    if( sqlite3VdbeRecordCompare(p2->nKey, p2->aKey, r1)>=0 ){
      iRes = i1;
    }else{
      iRes = i2;
    }
    sqlite3VdbeDeleteUnpackedRecord(r1);
  }

  pSorter->aTree[iOut] = iRes;
  return SQLITE_OK;
}

/*
** Initialize the temporary index cursor just opened as a sorter cursor.
*/
int sqlite3VdbeSorterInit(sqlite3 *db, VdbeCursor *pCsr){


  assert( pCsr->pKeyInfo && pCsr->pBt );
  pCsr->pSorter = sqlite3DbMallocZero(db, sizeof(VdbeSorter));

  return (pCsr->pSorter ? SQLITE_OK : SQLITE_NOMEM);




















}

/*
** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
*/
void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
  VdbeSorter *pSorter = pCsr->pSorter;
................................................................................
        vdbeSorterIterZero(db, &pSorter->aIter[i]);
      }
      sqlite3DbFree(db, pSorter->aIter);
    }
    if( pSorter->pTemp1 ){
      sqlite3OsCloseFree(pSorter->pTemp1);
    }

    sqlite3DbFree(db, pSorter);
    pCsr->pSorter = 0;
  }
}

/*
** Allocate space for a file-handle and open a temporary file. If successful,
................................................................................
  return sqlite3OsOpenMalloc(db->pVfs, 0, ppFile,
      SQLITE_OPEN_TEMP_JOURNAL |
      SQLITE_OPEN_READWRITE    | SQLITE_OPEN_CREATE |
      SQLITE_OPEN_EXCLUSIVE    | SQLITE_OPEN_DELETEONCLOSE, &dummy
  );
}




















































/*




































































** Write the current contents of the b-tree to a PMA. Return SQLITE_OK
** if successful, or an SQLite error code otherwise.
**
** The format of a PMA is:
**
**     * A varint. This varint contains the total number of bytes of content
**       in the PMA (not including the varint itself).
**
**     * One or more records packed end-to-end in order of ascending keys. 
**       Each record consists of a varint followed by a blob of data (the 
**       key). The varint is the number of bytes in the blob of data.
*/
static int vdbeSorterBtreeToPMA(sqlite3 *db, VdbeCursor *pCsr){
  int rc = SQLITE_OK;             /* Return code */
  VdbeSorter *pSorter = pCsr->pSorter;
  int res = 0;


  /* sqlite3BtreeFirst() cannot fail because sorter btrees are always held
  ** in memory and so an I/O error is not possible. */
  rc = sqlite3BtreeFirst(pCsr->pCursor, &res);
  if( NEVER(rc!=SQLITE_OK) || res ) return rc;


  assert( pSorter->nBtree>0 );

  /* If the first temporary PMA file has not been opened, open it now. */
  if( pSorter->pTemp1==0 ){
    rc = vdbeSorterOpenTempFile(db, &pSorter->pTemp1);
    assert( rc!=SQLITE_OK || pSorter->pTemp1 );
    assert( pSorter->iWriteOff==0 );
    assert( pSorter->nPMA==0 );
  }

  if( rc==SQLITE_OK ){
    i64 iWriteOff = pSorter->iWriteOff;
    void *aMalloc = 0;            /* Array used to hold a single record */
    int nMalloc = 0;              /* Allocated size of aMalloc[] in bytes */

    pSorter->nPMA++;
    for(
      rc = vdbeSorterWriteVarint(pSorter->pTemp1, pSorter->nBtree, &iWriteOff);
      rc==SQLITE_OK && res==0;
      rc = sqlite3BtreeNext(pCsr->pCursor, &res)
    ){
      i64 nKey;                   /* Size of this key in bytes */

      /* Write the size of the record in bytes to the output file */
      (void)sqlite3BtreeKeySize(pCsr->pCursor, &nKey);

      rc = vdbeSorterWriteVarint(pSorter->pTemp1, nKey, &iWriteOff);

      /* Make sure the aMalloc[] buffer is large enough for the record */
      if( rc==SQLITE_OK && nKey>nMalloc ){
        aMalloc = sqlite3DbReallocOrFree(db, aMalloc, nKey);
        if( !aMalloc ){ 
          rc = SQLITE_NOMEM; 
        }else{
          nMalloc = nKey;
        }
      }

      /* Write the record itself to the output file */
      if( rc==SQLITE_OK ){
        /* sqlite3BtreeKey() cannot fail because sorter btrees held in memory */
        rc = sqlite3BtreeKey(pCsr->pCursor, 0, nKey, aMalloc);
        if( ALWAYS(rc==SQLITE_OK) ){
          rc = sqlite3OsWrite(pSorter->pTemp1, aMalloc, nKey, iWriteOff);
          iWriteOff += nKey;
        }
      }

      if( rc!=SQLITE_OK ) break;


    }

    /* This assert verifies that unless an error has occurred, the size of 
    ** the PMA on disk is the same as the expected size stored in
    ** pSorter->nBtree. */ 
    assert( rc!=SQLITE_OK || pSorter->nBtree==(
          iWriteOff-pSorter->iWriteOff-sqlite3VarintLen(pSorter->nBtree)
    ));

    pSorter->iWriteOff = iWriteOff;
    sqlite3DbFree(db, aMalloc);
  }

  pSorter->nBtree = 0;
  return rc;
}

/*
** This function is called on a sorter cursor by the VDBE before each row 
** is inserted into VdbeCursor.pCsr. Argument nKey is the size of the key, in
** bytes, about to be inserted.
**
** If it is determined that the temporary b-tree accessed via VdbeCursor.pCsr
** is large enough, its contents are written to a sorted PMA on disk and the
** tree emptied. This prevents the b-tree (which must be small enough to
** fit entirely in the cache in order to support efficient inserts) from
** growing too large.
**
** An SQLite error code is returned if an error occurs. Otherwise, SQLITE_OK.
*/
int sqlite3VdbeSorterWrite(sqlite3 *db, VdbeCursor *pCsr, int nKey){
  int rc = SQLITE_OK;             /* Return code */
  VdbeSorter *pSorter = pCsr->pSorter;
  if( pSorter ){
    Pager *pPager = sqlite3BtreePager(pCsr->pBt);
    int nPage;                    /* Current size of temporary file in pages */

    /* Sorters never spill to disk */
    assert( sqlite3PagerFile(pPager)->pMethods==0 );

    /* Determine how many pages the temporary b-tree has grown to */
    sqlite3PagerPagecount(pPager, &nPage);

    /* If pSorter->nWorking is still zero, but the temporary file has been
    ** created in the file-system, then the most recent insert into the
    ** current b-tree segment probably caused the cache to overflow (it is
    ** also possible that sqlite3_release_memory() was called). So set the
    ** size of the working set to a little less than the current size of the 
    ** file in pages.  */
    if( pSorter->nWorking==0 && sqlite3PagerUnderStress(pPager) ){
      pSorter->nWorking = nPage-5;
      if( pSorter->nWorking<SORTER_MIN_WORKING ){
        pSorter->nWorking = SORTER_MIN_WORKING;
      }
    }

    /* If the number of pages used by the current b-tree segment is greater
    ** than the size of the working set (VdbeSorter.nWorking), start a new
    ** segment b-tree.  */
    if( pSorter->nWorking && nPage>=pSorter->nWorking ){
      BtCursor *p = pCsr->pCursor;/* Cursor structure to close and reopen */
      int iRoot;                  /* Root page of new tree */

      /* Copy the current contents of the b-tree into a PMA in sorted order.
      ** Close the currently open b-tree cursor. */
      rc = vdbeSorterBtreeToPMA(db, pCsr);
      sqlite3BtreeCloseCursor(p);

      if( rc==SQLITE_OK ){
        rc = sqlite3BtreeDropTable(pCsr->pBt, 2, 0);
#ifdef SQLITE_DEBUG
        sqlite3PagerPagecount(pPager, &nPage);
        assert( rc!=SQLITE_OK || nPage==1 );
#endif
      }
      if( rc==SQLITE_OK ){
        rc = sqlite3BtreeCreateTable(pCsr->pBt, &iRoot, BTREE_BLOBKEY);
      }
      if( rc==SQLITE_OK ){
        assert( iRoot==2 );
        rc = sqlite3BtreeCursor(pCsr->pBt, iRoot, 1, pCsr->pKeyInfo, p);
      }
    }

    pSorter->nBtree += sqlite3VarintLen(nKey) + nKey;
  }
  return rc;
}

/*
** Helper function for sqlite3VdbeSorterRewind(). 
*/
static int vdbeSorterInitMerge(
................................................................................
  int nIter;                      /* Number of iterators used */
  int nByte;                      /* Bytes of space required for aIter/aTree */
  int N = 2;                      /* Power of 2 >= nIter */

  assert( pSorter );

  /* Write the current b-tree to a PMA. Close the b-tree cursor. */
  rc = vdbeSorterBtreeToPMA(db, pCsr);
  sqlite3BtreeCloseCursor(pCsr->pCursor);
  if( rc!=SQLITE_OK ) return rc;
  if( pSorter->nPMA==0 ){
    *pbEof = 1;
    return SQLITE_OK;
  }

  /* Allocate space for aIter[] and aTree[]. */
................................................................................
** Copy the current sorter key into the memory cell pOut.
*/
int sqlite3VdbeSorterRowkey(VdbeCursor *pCsr, Mem *pOut){
  VdbeSorter *pSorter = pCsr->pSorter;
  VdbeSorterIter *pIter;

  pIter = &pSorter->aIter[ pSorter->aTree[1] ];

  /* Coverage testing note: As things are currently, this call will always
  ** succeed. This is because the memory cell passed by the VDBE layer 
  ** happens to be the same one as was used to assemble the keys before they
  ** were passed to the sorter - meaning it is always large enough for the
  ** largest key. But this could change very easily, so we leave the call
  ** to sqlite3VdbeMemGrow() in. */
  if( NEVER(sqlite3VdbeMemGrow(pOut, pIter->nKey, 0)) ){
    return SQLITE_NOMEM;
  }
  pOut->n = pIter->nKey;
  MemSetTypeFlag(pOut, MEM_Blob);
  memcpy(pOut->z, pIter->aKey, pIter->nKey);

  return SQLITE_OK;
}



























#endif /* #ifndef SQLITE_OMIT_MERGE_SORT */







>







 







<
|







>
>
>







 







>
>
>
>
>
>
>
>
>
>
>







 







>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>







 







|
|
|
|
|
|
<
<
<




<










>
>
|

>
|
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>







 







>







 







>
>
>
>
>
>
>
>
>
>
>
>
>
>

>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>

>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
|
|










|


<

>
|
<
<
|
>
>
|


|







|
|
|


<
|
|
<
<
<
<
<
<
>
|

<
<
<
<
<
<
<
<
<
<
<

<
<
<
|
|
|
|
<
<
>
>




|
|
|


|
|


<




|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<
<







 







|
<







 







<
<
<
<
<
<
<
|









>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>

17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
..
89
90
91
92
93
94
95

96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
...
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
...
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
...
360
361
362
363
364
365
366
367
368
369
370
371
372



373
374
375
376

377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
...
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
...
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585

586
587
588


589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607

608
609






610
611
612











613



614
615
616
617


618
619
620
621
622
623
624
625
626
627
628
629
630
631
632

633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685



















686
687
688
689
690
691
692
...
729
730
731
732
733
734
735
736

737
738
739
740
741
742
743
...
843
844
845
846
847
848
849







850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886

#include "sqliteInt.h"
#include "vdbeInt.h"

#ifndef SQLITE_OMIT_MERGE_SORT

typedef struct VdbeSorterIter VdbeSorterIter;
typedef struct SorterRecord SorterRecord;

/*
** NOTES ON DATA STRUCTURE USED FOR N-WAY MERGES:
**
** As keys are added to the sorter, they are written to disk in a series
** of sorted packed-memory-arrays (PMAs). The size of each PMA is roughly
** the same as the cache-size allowed for temporary databases. In order
................................................................................
**     aTree[] = { X, 0   0, 6    0, 3, 5, 6 }
**
** In other words, each time we advance to the next sorter element, log2(N)
** key comparison operations are required, where N is the number of segments
** being merged (rounded up to the next power of 2).
*/
struct VdbeSorter {

  int nInMemory;                  /* Current size of b-tree contents as PMA */
  int nTree;                      /* Used size of aTree/aIter (power of 2) */
  VdbeSorterIter *aIter;          /* Array of iterators to merge */
  int *aTree;                     /* Current state of incremental merge */
  i64 iWriteOff;                  /* Current write offset within file pTemp1 */
  i64 iReadOff;                   /* Current read offset within file pTemp1 */
  sqlite3_file *pTemp1;           /* PMA file 1 */
  int nPMA;                       /* Number of PMAs stored in pTemp1 */
  SorterRecord *pRecord;          /* Head of in-memory record list */
  int nLimit1;                    /* Minimum PMA size, in bytes */
  int nLimit2;                    /* Maximum PMA size, in bytes */
};

/*
** The following type is an iterator for a PMA. It caches the current key in 
** variables nKey/aKey. If the iterator is at EOF, pFile==0.
*/
struct VdbeSorterIter {
................................................................................
  i64 iEof;                       /* 1 byte past EOF for this iterator */
  sqlite3_file *pFile;            /* File iterator is reading from */
  int nAlloc;                     /* Bytes of space at aAlloc */
  u8 *aAlloc;                     /* Allocated space */
  int nKey;                       /* Number of bytes in key */
  u8 *aKey;                       /* Pointer to current key */
};

/*
** A structure to store a single record. All in-memory records are connected
** together into a linked list headed at VdbeSorter.pRecord using the 
** SorterRecord.pNext pointer.
*/
struct SorterRecord {
  void *pVal;
  int nVal;
  SorterRecord *pNext;
};

/* Minimum allowable value for the VdbeSorter.nWorking variable */
#define SORTER_MIN_WORKING 10

/* Maximum number of segments to merge in a single pass. */
#define SORTER_MAX_MERGE_COUNT 16

................................................................................
  }
  if( rc==SQLITE_OK ){
    rc = vdbeSorterIterNext(db, pIter);
  }
  return rc;
}


/*
** Compare key1 (buffer pKey1, size nKey1 bytes) with key2 (buffer pKey2, 
** size nKey2 bytes).  Argument pKeyInfo supplies the collation functions
** used by the comparison. If an error occurs, return an SQLite error code.
** Otherwise, return SQLITE_OK and set *pRes to a negative, zero or positive
** value, depending on whether key1 is smaller, equal to or larger than key2.
**
** If the bOmitRowid argument is non-zero, assume both keys end in a rowid
** field. For the purposes of the comparison, ignore it. Also, if bOmitRowid
** is true and key1 contains even a single NULL value, it is considered to
** be less than key2. Even if key2 also contains NULL values.
*/
static int vdbeSorterCompare(
  KeyInfo *pKeyInfo,              /* Collation functions to use in comparison */
  int bOmitRowid,                 /* Ignore rowid field at end of keys */
  void *pKey1, int nKey1,         /* Left side of comparison */
  void *pKey2, int nKey2,         /* Right side of comparison */
  int *pRes                       /* OUT: Result of comparison */
){
  char aSpace[150];
  UnpackedRecord *r2;
  int i;

  r2 = sqlite3VdbeRecordUnpack(pKeyInfo, nKey2, pKey2, aSpace, sizeof(aSpace));
  if( r2==0 ) return SQLITE_NOMEM;
  if( bOmitRowid ){
    for(i=0; i<r2->nField-1; i++){
      if( r2->aMem[i].flags & MEM_Null ){
        *pRes = -1;
        sqlite3VdbeDeleteUnpackedRecord(r2);
        return SQLITE_OK;
      }
    }
    r2->flags |= UNPACKED_PREFIX_MATCH;
    r2->nField--;
    assert( r2->nField>0 );
  }

  *pRes = sqlite3VdbeRecordCompare(nKey1, pKey1, r2);
  sqlite3VdbeDeleteUnpackedRecord(r2);
  return SQLITE_OK;
}

/*
** This function is called to compare two iterator keys when merging 
** multiple b-tree segments. Parameter iOut is the index of the aTree[] 
** value to recalculate.
*/
static int vdbeSorterDoCompare(VdbeCursor *pCsr, int iOut){
  VdbeSorter *pSorter = pCsr->pSorter;
................................................................................
  p2 = &pSorter->aIter[i2];

  if( p1->pFile==0 ){
    iRes = i2;
  }else if( p2->pFile==0 ){
    iRes = i1;
  }else{
    int res;
    int rc = vdbeSorterCompare(
        pCsr->pKeyInfo, 0, p1->aKey, p1->nKey, p2->aKey, p2->nKey, &res
    );
    if( rc!=SQLITE_OK ) return rc;
    if( res<=0 ){



      iRes = i1;
    }else{
      iRes = i2;
    }

  }

  pSorter->aTree[iOut] = iRes;
  return SQLITE_OK;
}

/*
** Initialize the temporary index cursor just opened as a sorter cursor.
*/
int sqlite3VdbeSorterInit(sqlite3 *db, VdbeCursor *pCsr){
  int pgsz;                       /* Page size of main database */

  assert( pCsr->pKeyInfo && pCsr->pBt==0 );
  pCsr->pSorter = sqlite3DbMallocZero(db, sizeof(VdbeSorter));
  if( pCsr->pSorter==0 ){
    return SQLITE_NOMEM;
  }

  pgsz = sqlite3BtreeGetPageSize(db->aDb[0].pBt);
  pCsr->pSorter->nLimit1 = 10 * pgsz;
  pCsr->pSorter->nLimit2 = db->aDb[0].pSchema->cache_size * pgsz;

  return SQLITE_OK;
}

/*
** Free the list of sorted records starting at pRecord.
*/
static void vdbeSorterRecordFree(sqlite3 *db, SorterRecord *pRecord){
  SorterRecord *p;
  SorterRecord *pNext;
  for(p=pRecord; p; p=pNext){
    pNext = p->pNext;
    sqlite3DbFree(db, p->pVal);
    sqlite3DbFree(db, p);
  }
}

/*
** Free any cursor components allocated by sqlite3VdbeSorterXXX routines.
*/
void sqlite3VdbeSorterClose(sqlite3 *db, VdbeCursor *pCsr){
  VdbeSorter *pSorter = pCsr->pSorter;
................................................................................
        vdbeSorterIterZero(db, &pSorter->aIter[i]);
      }
      sqlite3DbFree(db, pSorter->aIter);
    }
    if( pSorter->pTemp1 ){
      sqlite3OsCloseFree(pSorter->pTemp1);
    }
    vdbeSorterRecordFree(db, pSorter->pRecord);
    sqlite3DbFree(db, pSorter);
    pCsr->pSorter = 0;
  }
}

/*
** Allocate space for a file-handle and open a temporary file. If successful,
................................................................................
  return sqlite3OsOpenMalloc(db->pVfs, 0, ppFile,
      SQLITE_OPEN_TEMP_JOURNAL |
      SQLITE_OPEN_READWRITE    | SQLITE_OPEN_CREATE |
      SQLITE_OPEN_EXCLUSIVE    | SQLITE_OPEN_DELETEONCLOSE, &dummy
  );
}

/*
** Attemp to merge the two sorted lists p1 and p2 into a single list. If no
** error occurs set *ppOut to the head of the new list and return SQLITE_OK.
*/
static int vdbeSorterMerge(
  sqlite3 *db,                    /* Database handle */
  KeyInfo *pKeyInfo,              /* Collation functions to use in comparison */
  SorterRecord *p1,               /* First list to merge */
  SorterRecord *p2,               /* Second list to merge */
  SorterRecord **ppOut            /* OUT: Head of merged list */
){
  int rc = SQLITE_OK;
  SorterRecord *pFinal = 0;
  SorterRecord **pp = &pFinal;

  while( p1 || p2 ){
    if( p1==0 ){
      *pp = p2;
      p2 = 0;
    }else if( p2==0 ){
      *pp = p1;
      p1 = 0;
    }else{
      int res;
      rc = vdbeSorterCompare(
          pKeyInfo, 0, p1->pVal, p1->nVal, p2->pVal, p2->nVal, &res
      );
      if( rc!=SQLITE_OK ){
        vdbeSorterRecordFree(db, p1);
        vdbeSorterRecordFree(db, p2);
        vdbeSorterRecordFree(db, pFinal);
        pFinal = 0;
        break;
      }
      if( res<=0 ){
        *pp = p1;
        pp = &p1->pNext;
        p1 = p1->pNext;
      }else{
        *pp = p2;
        pp = &p2->pNext;
        p2 = p2->pNext;
      }
      *pp = 0;
    }
  }

  *ppOut = pFinal;
  return rc;
}

/*
** Sort the linked list of records headed at pCsr->pRecord. Return SQLITE_OK
** if successful, or an SQLite error code (i.e. SQLITE_NOMEM) if an error
** occurs.
*/
static int vdbeSorterSort(sqlite3 *db, VdbeCursor *pCsr){
  int rc = SQLITE_OK;
  int i;
  SorterRecord **aSlot;
  SorterRecord *p;
  VdbeSorter *pSorter = pCsr->pSorter;
  KeyInfo *pKeyInfo = pCsr->pKeyInfo;

  aSlot = (SorterRecord **)sqlite3MallocZero(64 * sizeof(SorterRecord *));
  if( !aSlot ){
    return SQLITE_NOMEM;
  }

  p = pSorter->pRecord;
  while( p ){
    SorterRecord *pNext = p->pNext;
    p->pNext = 0;
    for(i=0; rc==SQLITE_OK && aSlot[i]; i++){
      rc = vdbeSorterMerge(db, pKeyInfo, p, aSlot[i], &p);
      aSlot[i] = 0;
    }
    if( rc!=SQLITE_OK ){
      vdbeSorterRecordFree(db, pNext);
      break;
    }
    aSlot[i] = p;
    p = pNext;
  }

  p = 0;
  for(i=0; i<64; i++){
    if( rc==SQLITE_OK ){
      rc = vdbeSorterMerge(db, pKeyInfo, p, aSlot[i], &p);
    }else{
      vdbeSorterRecordFree(db, aSlot[i]);
    }
  }
  pSorter->pRecord = p;

#if 0
  {
    SorterRecord *pTmp1 = 0;
    SorterRecord *pTmp2;
    for(pTmp2=pSorter->pRecord; pTmp2 && rc==SQLITE_OK; pTmp2=pTmp2->pNext){
      if( pTmp1 ){
        int res;
        rc = vdbeSorterCompare(pKeyInfo, 
            0, pTmp1->pVal, pTmp1->nVal, pTmp2->pVal, pTmp2->nVal, &res
        );
        assert( rc!=SQLITE_OK || res<0 );
      }
      pTmp1 = pTmp2;
    }
  }
#endif

  if( rc!=SQLITE_OK ){
  }
  sqlite3_free(aSlot);
  return rc;
}


/*
** Write the current contents of the in-memory linked-list to a PMA. Return
** SQLITE_OK if successful, or an SQLite error code otherwise.
**
** The format of a PMA is:
**
**     * A varint. This varint contains the total number of bytes of content
**       in the PMA (not including the varint itself).
**
**     * One or more records packed end-to-end in order of ascending keys. 
**       Each record consists of a varint followed by a blob of data (the 
**       key). The varint is the number of bytes in the blob of data.
*/
static int vdbeSorterListToPMA(sqlite3 *db, VdbeCursor *pCsr){
  int rc = SQLITE_OK;             /* Return code */
  VdbeSorter *pSorter = pCsr->pSorter;


  if( pSorter->nInMemory==0 ){
    assert( pSorter->pRecord==0 );


    return rc;
  }

  rc = vdbeSorterSort(db, pCsr);

  /* If the first temporary PMA file has not been opened, open it now. */
  if( rc==SQLITE_OK && pSorter->pTemp1==0 ){
    rc = vdbeSorterOpenTempFile(db, &pSorter->pTemp1);
    assert( rc!=SQLITE_OK || pSorter->pTemp1 );
    assert( pSorter->iWriteOff==0 );
    assert( pSorter->nPMA==0 );
  }

  if( rc==SQLITE_OK ){
    i64 iOff = pSorter->iWriteOff;
    SorterRecord *p;
    SorterRecord *pNext = 0;

    pSorter->nPMA++;

    rc = vdbeSorterWriteVarint(pSorter->pTemp1, pSorter->nInMemory, &iOff);
    for(p=pSorter->pRecord; rc==SQLITE_OK && p; p=pNext){






      pNext = p->pNext;
      rc = vdbeSorterWriteVarint(pSorter->pTemp1, p->nVal, &iOff);












      if( rc==SQLITE_OK ){



        rc = sqlite3OsWrite(pSorter->pTemp1, p->pVal, p->nVal, iOff);
        iOff += p->nVal;
      }



      sqlite3DbFree(db, p->pVal);
      sqlite3DbFree(db, p);
    }

    /* This assert verifies that unless an error has occurred, the size of 
    ** the PMA on disk is the same as the expected size stored in
    ** pSorter->nInMemory. */ 
    assert( rc!=SQLITE_OK || pSorter->nInMemory==(
          iOff-pSorter->iWriteOff-sqlite3VarintLen(pSorter->nInMemory)
    ));

    pSorter->iWriteOff = iOff;
    pSorter->pRecord = p;
  }


  return rc;
}

/*
** Add a record to the sorter.
*/
int sqlite3VdbeSorterWrite(
  sqlite3 *db,                    /* Database handle */
  VdbeCursor *pCsr,               /* Sorter cursor */
  Mem *pVal                       /* Memory cell containing record */
){
  VdbeSorter *pSorter = pCsr->pSorter;
  int rc;
  SorterRecord *pNew;

  assert( pSorter );
  pSorter->nInMemory += sqlite3VarintLen(pVal->n) + pVal->n;

  pNew = (SorterRecord *)sqlite3DbMallocZero(db, sizeof(SorterRecord));
  if( pNew==0 ){
    rc = SQLITE_NOMEM;
  }else{
    rc = sqlite3VdbeMemMakeWriteable(pVal);
    if( rc==SQLITE_OK ){
      pNew->pVal = pVal->z;
      pNew->nVal = pVal->n;
      pVal->zMalloc = 0;
      sqlite3VdbeMemSetNull(pVal);
      pNew->pNext = pSorter->pRecord;
      pSorter->pRecord = pNew;
    }else{
      sqlite3DbFree(db, pNew);
      rc = SQLITE_NOMEM;
    }
  }

  /* See if the contents of the sorter should now be written out. They
  ** are written out when either of the following are true:
  **
  **   * The total memory allocated for the in-memory list is greater 
  **     than (page-size * cache-size), or
  **
  **   * The total memory allocated for the in-memory list is greater 
  **     than (page-size * 10) and sqlite3HeapNearlyFull() returns true.
  */
  if( rc==SQLITE_OK && (
        (pSorter->nInMemory>pSorter->nLimit2)
     || (pSorter->nInMemory>pSorter->nLimit1 && sqlite3HeapNearlyFull())
  )){
    rc = vdbeSorterListToPMA(db, pCsr);
    pSorter->nInMemory = 0;
  }




















  return rc;
}

/*
** Helper function for sqlite3VdbeSorterRewind(). 
*/
static int vdbeSorterInitMerge(
................................................................................
  int nIter;                      /* Number of iterators used */
  int nByte;                      /* Bytes of space required for aIter/aTree */
  int N = 2;                      /* Power of 2 >= nIter */

  assert( pSorter );

  /* Write the current b-tree to a PMA. Close the b-tree cursor. */
  rc = vdbeSorterListToPMA(db, pCsr);

  if( rc!=SQLITE_OK ) return rc;
  if( pSorter->nPMA==0 ){
    *pbEof = 1;
    return SQLITE_OK;
  }

  /* Allocate space for aIter[] and aTree[]. */
................................................................................
** Copy the current sorter key into the memory cell pOut.
*/
int sqlite3VdbeSorterRowkey(VdbeCursor *pCsr, Mem *pOut){
  VdbeSorter *pSorter = pCsr->pSorter;
  VdbeSorterIter *pIter;

  pIter = &pSorter->aIter[ pSorter->aTree[1] ];







  if( sqlite3VdbeMemGrow(pOut, pIter->nKey, 0) ){
    return SQLITE_NOMEM;
  }
  pOut->n = pIter->nKey;
  MemSetTypeFlag(pOut, MEM_Blob);
  memcpy(pOut->z, pIter->aKey, pIter->nKey);

  return SQLITE_OK;
}

/*
** Compare the key in memory cell pVal with the key that the sorter cursor
** passed as the first argument currently points to. For the purposes of
** the comparison, ignore the rowid field at the end of each record.
**
** If an error occurs, return an SQLite error code (i.e. SQLITE_NOMEM).
** Otherwise, set *pRes to a negative, zero or positive value if the
** key in pVal is smaller than, equal to or larger than the current sorter
** key.
*/
int sqlite3VdbeSorterCompare(
  VdbeCursor *pCsr,               /* Sorter cursor */
  Mem *pVal,                      /* Value to compare to current sorter key */
  int *pRes                       /* OUT: Result of comparison */
){
  int rc;
  VdbeSorter *pSorter = pCsr->pSorter;
  VdbeSorterIter *pIter;
  pIter = &pSorter->aIter[ pSorter->aTree[1] ];
  rc = vdbeSorterCompare(pCsr->pKeyInfo, 1,
      pVal->z, pVal->n, pIter->aKey, pIter->nKey, pRes
  );
  assert( rc!=SQLITE_OK || *pRes<=0 );
  return rc;
}

#endif /* #ifndef SQLITE_OMIT_MERGE_SORT */

Changes to test/index4.test.

104
105
106
107
108
109
110









111





112
    DROP TABLE t1;
    CREATE TABLE t1(x);
  COMMIT;
  CREATE INDEX i1 ON t1(x); 
  PRAGMA integrity_check
} {ok}
















finish_test







>
>
>
>
>
>
>
>
>
|
>
>
>
>
>

104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
    DROP TABLE t1;
    CREATE TABLE t1(x);
  COMMIT;
  CREATE INDEX i1 ON t1(x); 
  PRAGMA integrity_check
} {ok}

do_execsql_test 2.1 {
  BEGIN;
    CREATE TABLE t2(x);
    INSERT INTO t2 VALUES(14);
    INSERT INTO t2 VALUES(35);
    INSERT INTO t2 VALUES(15);
    INSERT INTO t2 VALUES(35);
    INSERT INTO t2 VALUES(16);
  COMMIT;
}
do_catchsql_test 2.2 {
  CREATE UNIQUE INDEX i3 ON t2(x);
} {1 {indexed columns are not unique}}


finish_test