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Overview
| Comment: | Reduce the number of cases where it is necessary to check for NULL after the loop terminating condition. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
3c1ae447dec8fc2af1c5105134061717 |
| User & Date: | drh 2014-02-14 20:59:53 |
Context
|
2014-02-14
| ||
| 23:49 | Seek past NULLs in a top-constrained search. Avoid checking for NULLs in the body of the search. (check-in: e07a32f3 user: drh tags: trunk) | |
| 23:35 | Better support for MinGW 4.x. (check-in: e1472307 user: mistachkin tags: mingw4x) | |
| 20:59 | Reduce the number of cases where it is necessary to check for NULL after the loop terminating condition. (check-in: 3c1ae447 user: drh tags: trunk) | |
| 15:13 | Add OP_IdxGT and OP_IdxLE as distinct opcodes. Formerly these operations where done using OP_IdxGE and OP_IdxLT with the P5 flag set. But VDBE code is easier to read with distinct opcode names. Also change OP_SeekGe to OP_SeekGE, and so forth, so that the capitalization is consistent. The whole point of this change is to improve the readability of VDBE listings. (check-in: b6bea903 user: drh tags: trunk) | |
Changes
Changes to src/where.c.
3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 |
testcase( op==OP_IdxGT );
testcase( op==OP_IdxGE );
testcase( op==OP_IdxLT );
testcase( op==OP_IdxLE );
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
}
/* If there are inequality constraints, check that the value
** of the table column that the inequality contrains is not NULL.
** If it is, jump to the next iteration of the loop.
*/
r1 = sqlite3GetTempReg(pParse);
testcase( pLoop->wsFlags & WHERE_BTM_LIMIT );
testcase( pLoop->wsFlags & WHERE_TOP_LIMIT );
if( (pLoop->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
&& (j = pIdx->aiColumn[nEq])>=0
&& pIdx->pTable->aCol[j].notNull==0
&& (nEq || (pLoop->wsFlags & WHERE_BTM_LIMIT)==0)
){
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1);
VdbeComment((v, "%s", pIdx->pTable->aCol[j].zName));
sqlite3VdbeAddOp2(v, OP_IsNull, r1, addrCont);
}
sqlite3ReleaseTempReg(pParse, r1);
|
| > | < > < < | < |
3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 |
testcase( op==OP_IdxGT );
testcase( op==OP_IdxGE );
testcase( op==OP_IdxLT );
testcase( op==OP_IdxLE );
sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
}
/* If there are inequality constraint upper bound but not a lower
** bound, then check that the value of the table column that the
** inequality contrains is not NULL since there is alway an implied
** lower bound of "column>NULL".
*/
r1 = sqlite3GetTempReg(pParse);
if( (pLoop->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==WHERE_TOP_LIMIT
&& (j = pIdx->aiColumn[nEq])>=0
&& pIdx->pTable->aCol[j].notNull==0
){
sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1);
VdbeComment((v, "%s", pIdx->pTable->aCol[j].zName));
sqlite3VdbeAddOp2(v, OP_IsNull, r1, addrCont);
}
sqlite3ReleaseTempReg(pParse, r1);
|