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Provide an estimated row count to stat_init() for STAT1 analysis.

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FossilOrigin-Name: 714419fe85cfdad22979183a94e4569c87740652758ab76b646753cf2b013b54
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drh
2020-03-17 17:11:23 +00:00
parent e50478d727
commit 9f27463684
4 changed files with 53 additions and 46 deletions
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18
src/vdbe.c
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@@ -3187,11 +3187,15 @@ case OP_MakeRecord: {
break;
}
/* Opcode: Count P1 P2 * * *
/* Opcode: Count P1 P2 p3 * *
** Synopsis: r[P2]=count()
**
** Store the number of entries (an integer value) in the table or index
** opened by cursor P1 in register P2
** opened by cursor P1 in register P2.
**
** If P3==0, then an exact count is obtained, which involves visiting
** every btree page of the table. But if P3 is non-zero, an estimate
** is returned based on the current cursor position.
*/
case OP_Count: { /* out2 */
i64 nEntry;
@@ -3200,9 +3204,13 @@ case OP_Count: { /* out2 */
assert( p->apCsr[pOp->p1]->eCurType==CURTYPE_BTREE );
pCrsr = p->apCsr[pOp->p1]->uc.pCursor;
assert( pCrsr );
nEntry = 0; /* Not needed. Only used to silence a warning. */
rc = sqlite3BtreeCount(db, pCrsr, &nEntry);
if( rc ) goto abort_due_to_error;
if( pOp->p3 ){
nEntry = sqlite3BtreeRowCountEst(pCrsr);
}else{
nEntry = 0; /* Not needed. Only used to silence a warning. */
rc = sqlite3BtreeCount(db, pCrsr, &nEntry);
if( rc ) goto abort_due_to_error;
}
pOut = out2Prerelease(p, pOp);
pOut->u.i = nEntry;
goto check_for_interrupt;