SQLite4  Check-in [bad9060b5b]

  int regNumDLt = iMem++;      /* Number of distinct keys less than regSample */
  int regSample = iMem++;      /* The next sample value */
  int regAccum = iMem++;       /* Register to hold Stat3Accum object */
  int regLoop = iMem++;        /* Loop counter */
  int regCount = iMem++;       /* Number of rows in the table or index */
  int regTemp1 = iMem++;       /* Intermediate register */
  int regTemp2 = iMem++;       /* Intermediate register */
  int regNewSample = iMem++;
  int once = 1;                /* One-time initialization */
  int iTabCur = pParse->nTab++; /* Table cursor */
  int addrEq;
#endif
  int regRec = iMem++;         /* Register holding completed record */
  int regTemp = iMem++;        /* Temporary use register */
  int regNewRowid = iMem++;    /* Rowid for the inserted record */

    */
    regCnt = iMem;
    regPrev = iMem+1;
    aregCard = iMem+2;

    sqlite4VdbeAddOp2(v, OP_Integer, 0, regCnt);
    sqlite4VdbeAddOp2(v, OP_Null, 0, regPrev);
    sqlite4VdbeAddOp2(v, OP_Null, 0, regSample);
    for(i=0; i<nCol; i++){
      sqlite4VdbeAddOp2(v, OP_Integer, 1, aregCard+i);
    }

    /* Start the analysis loop. This loop runs through all the entries in
    ** the index b-tree.  */
    endOfLoop = sqlite4VdbeMakeLabel(v);
    sqlite4VdbeAddOp2(v, OP_Rewind, iIdxCur, endOfLoop);
    topOfLoop = sqlite4VdbeCurrentAddr(v);
    sqlite4VdbeAddOp2(v, OP_AddImm, regCnt, 1);  /* Increment row counter */



    sqlite4VdbeAddOp4Int(v, OP_AnalyzeKey, iIdxCur, regPrev, aregCard, nCol);

#ifdef SQLITE4_ENABLE_STAT3
    sqlite4VdbeAddOp2(v, OP_RowKey, iIdxCur, regNewSample);
    sqlite4VdbeChangeP5(v, 1);
    addrEq = sqlite4VdbeAddOp3(v, OP_Eq, regNewSample, 0, regSample);
    addrIsnull = sqlite4VdbeAddOp2(v, OP_IsNull, regSample, 0);

    assert( regNumEq==regNumLt-1  && regNumEq==regNumDLt-2
         && regNumEq==regSample-3 && regNumEq==regAccum-4
    );


    sqlite4VdbeAddOp4(v, OP_Function, 1, regNumEq, regTemp2, 
        (char*)&stat3PushFuncdef, P4_FUNCDEF
    );
    sqlite4VdbeChangeP5(v, 5);
    sqlite4VdbeAddOp3(v, OP_Add, regNumEq, regNumLt, regNumLt);
    sqlite4VdbeAddOp2(v, OP_AddImm, regNumDLt, 1);

    sqlite4VdbeJumpHere(v, addrIsnull);
    sqlite4VdbeAddOp2(v, OP_Integer, 0, regNumEq);
    sqlite4VdbeAddOp2(v, OP_Copy, regNewSample, regSample);
    sqlite4VdbeJumpHere(v, addrEq);
    sqlite4VdbeAddOp2(v, OP_AddImm, regNumEq, 1);
#endif

    /* Always jump here after updating the iMem+1...iMem+1+nCol counters */
    sqlite4VdbeResolveLabel(v, endOfLoop);

    sqlite4VdbeAddOp2(v, OP_Next, iIdxCur, topOfLoop);
    sqlite4VdbeAddOp1(v, OP_Close, iIdxCur);


#ifdef SQLITE4_ENABLE_STAT3
    /* Push the last record (if any) to the accumulator. */
    sqlite4VdbeAddOp4(v, OP_Function, 1, regNumEq, regTemp2,
                      (char*)&stat3PushFuncdef, P4_FUNCDEF);
    sqlite4VdbeChangeP5(v, 5);

    /* This block codes a loop that iterates through all entries stored
    ** by the accumulator (the Stat3Accum object). 

/* Opcode: AnalyzeKey P1 P2 P3 P4
**
** P1 is an open cursor that currently points to a valid row. P2 is a 
** register that contains either a NULL value, or an index key. If it is 
** not NULL, this opcode compares the key in register P2 with the key of 
** the row P1 currently points to and determines the number of fields in
** the prefix that the two keys share in common (which may be zero).
** Call this value N. If P2 is NULL, set N to P4.
**
** P3 is the first in an array of P4 registers containing integer values.
** The first N of these are left as is by this instruction. The remaining
** (P4-N) are incremented.
**
** Finally, the key belonging to the current row of cursor P1 is copied
** into register P2.

    if( pKey->flags & MEM_Blob ){
      for(i=0; i<nNew && i<pKey->n && pNew[i]==(KVByteArray)pKey->z[i]; i++);

      /* The two keys share i bytes in common. Figure out how many fields
      ** this corresponds to. Store said value in variable nEq. */
      sqlite4VdbeShortKey(pNew, i, LARGEST_INT32, &nEq);
    }else{
      nEq = nTotal;
    }

    /* Increment nTotal-nEq registers */
    for(i=nEq; i<nTotal; i++){
      memAboutToChange(p, &aIncr[i]);
      sqlite4VdbeMemIntegerify(&aIncr[i]);
      aIncr[i].u.num = sqlite4_num_add(

# Verify that the t1b index shows that it does not narrow down the
# search any at all.
#
do_test analyze4-1.1 {
  db eval {
    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
  }
} {t1 {128 1} t1a {128 1} t1b {128 128}}

# Change half of the b values from NULL to a constant.  Verify
# that the number of rows selected in stat1 is half the total 
# number of rows.
#
do_test analyze4-1.2 {
  db eval {
    UPDATE t1 SET b='x' WHERE a%2;
    ANALYZE;
    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
  }
} {t1 {128 1} t1a {128 1} t1b {128 64}}

# Change the t1.b values all back to NULL.  Add columns t1.c and t1.d.
# Create a multi-column indices using t1.b and verify that ANALYZE 
# processes them correctly.
#
do_test analyze4-1.3 {
  db eval {
    UPDATE t1 SET b=NULL;
    ALTER TABLE t1 ADD COLUMN c;
    ALTER TABLE t1 ADD COLUMN d;
    UPDATE t1 SET c=a/4, d=a/2;
    CREATE INDEX t1bcd ON t1(b,c,d);
    CREATE INDEX t1cdb ON t1(c,d,b);
    CREATE INDEX t1cbd ON t1(c,b,d);
    ANALYZE;
    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t1' ORDER BY idx;
  }
} {t1 {128 1} t1a {128 1} t1b {128 128} t1bcd {128 128 4 2} t1cbd {128 4 4 2} t1cdb {128 4 2 2}}

# Verify that collating sequences are taken into account when computing
# ANALYZE statistics.
#
do_test analyze4-2.0 {
  db eval {
    CREATE TABLE t2(

    INSERT INTO t2 VALUES(5, 'aBc', 'aBc', 'aBc');
    INSERT INTO t2 VALUES(6, 'aBC', 'aBC', 'aBC');
    INSERT INTO t2 VALUES(7, 'aBc ', 'aBc ', 'aBc ');
    INSERT INTO t2 VALUES(8, 'aBC ', 'aBC ', 'aBC ');
    ANALYZE;
    SELECT idx, stat FROM sqlite_stat1 WHERE tbl='t2' ORDER BY idx;
  }
} {t2 {8 1} t2a {8 4} t2b {8 2} t2c {8 1} t2c2 {8 4} t2c3 {8 2}}

finish_test

  lsm1.test lsm2.test lsm3.test lsm4.test lsm5.test
  csr1.test
  ckpt1.test
  mc1.test
  fts5expr1.test fts5query1.test fts5rnd1.test fts5create.test
  fts5snippet.test

  analyze.test analyze3.test analyze4.test
  auth.test auth2.test auth3.test auth4.test
  aggerror.test
  attach.test
  autoindex1.test
  badutf.test
  between.test
  bigrow.test