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Overview
Comment: | Updates to the sqlite3_stmt_scanstatus() documentation. No changes to code. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
d97c324eb1d870c994911c53fbf84205 |
User & Date: | drh 2014-11-03 18:03:00.467 |
Context
2014-11-04
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12:11 | Add the SQLITE_CONFIG_PCACHE_HDRSZ option for sqlite3_config(). (check-in: 6eb03e62a3 user: drh tags: trunk) | |
2014-11-03
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18:03 | Updates to the sqlite3_stmt_scanstatus() documentation. No changes to code. (check-in: d97c324eb1 user: drh tags: trunk) | |
16:56 | Add the experimental sqlite3_stmt_scanstatus() API. For comparing the number of rows actually visited by a loop with the estimate used by the query planner. (check-in: ab3b0fc576 user: dan tags: trunk) | |
Changes
Changes to src/sqlite.h.in.
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7407 7408 7409 7410 7411 7412 7413 | */ #define SQLITE_ROLLBACK 1 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ #define SQLITE_FAIL 3 /* #define SQLITE_ABORT 4 // Also an error code */ #define SQLITE_REPLACE 5 | > | | | | | | | | | | | | | | | > > | | 7407 7408 7409 7410 7411 7412 7413 7414 7415 7416 7417 7418 7419 7420 7421 7422 7423 7424 7425 7426 7427 7428 7429 7430 7431 7432 7433 7434 7435 7436 7437 7438 7439 7440 7441 7442 7443 7444 7445 7446 7447 7448 7449 7450 7451 7452 7453 7454 7455 7456 7457 7458 7459 7460 7461 7462 7463 7464 7465 7466 7467 7468 7469 7470 7471 7472 7473 7474 7475 7476 7477 7478 7479 7480 7481 7482 7483 7484 7485 7486 7487 7488 7489 7490 7491 7492 7493 7494 7495 7496 7497 | */ #define SQLITE_ROLLBACK 1 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */ #define SQLITE_FAIL 3 /* #define SQLITE_ABORT 4 // Also an error code */ #define SQLITE_REPLACE 5 /* ** CAPI3REF: Prepared Statement Scan Status Opcodes ** KEYWORDS: {scanstatus options} ** ** The following constants can be used for the T parameter to the ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a ** different metric for sqlite3_stmt_scanstatus() to return. ** ** <dl> ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt> ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set to the ** total number of times that the X-th loop has run.</dd> ** ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt> ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set to the ** total number of rows visited by the X-th loop.</dd> ** ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt> ** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set to the ** query planner's estimate for the number of rows visited for each ** iteration of the X-th loop. If the query planner's estimate was accurate, ** then this value should be approximately NVISIT/NLOOP. ** ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt> ** <dd>^The "const char *" variable pointed to by the T parameter will be set to ** a zero-terminated UTF-8 string containing the name of the index or table used ** for the X-th loop. ** ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt> ** <dd>^The "const char *" variable pointed to by the T parameter will be set to ** a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN] description ** for the X-th loop. ** </dl> */ #define SQLITE_SCANSTAT_NLOOP 0 #define SQLITE_SCANSTAT_NVISIT 1 #define SQLITE_SCANSTAT_EST 2 #define SQLITE_SCANSTAT_NAME 3 #define SQLITE_SCANSTAT_EXPLAIN 4 /* ** CAPI3REF: Prepared Statement Scan Status ** ** Return status data for a single loop within query pStmt. ** ** The "iScanStatusOp" parameter determines which status information to return. ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior of ** this interface is undefined. ** ^The requested measurement is written into a variable pointed to by ** the "pOut" parameter. ** Parameter "idx" identifies the specific loop to retrieve statistics for. ** Loops are numbered starting from zero. ^If idx is out of range - less than ** zero or greater than or equal to the total number of loops used to implement ** the statement - a non-zero value is returned and the variable that pOut ** points to is unchanged. ** ** ^Statistics might not be available for all loops in all statements. ^In cases ** where there exist loops with no available statistics, this function behaves ** as if the loop did not exist - it returns non-zero and leave the variable ** that pOut points to unchanged. ** ** This API is only available if the library is built with pre-processor ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. ** ** See also: [sqlite3_stmt_scanstatus_reset()] */ SQLITE_EXPERIMENTAL int sqlite3_stmt_scanstatus( sqlite3_stmt *pStmt, /* Prepared statement for which info desired */ int idx, /* Index of loop to report on */ int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */ void *pOut /* Result written here */ ); /* ** CAPI3REF: Zero Scan-Status Counters ** ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters. ** ** This API is only available if the library is built with pre-processor ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined. */ SQLITE_EXPERIMENTAL void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*); |
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