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Overview
| Comment: | Revise the VDBE comments for NULL-scan so that they also work make sense when reading a NULLS FIRST plan. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | nulls-last |
| Files: | files | file ages | folders |
| SHA3-256: |
bfe793780fa6fc7a1e7d0ee60606dda2 |
| User & Date: | drh 2019-08-23 17:09:02 |
Context
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2019-08-23
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| 20:33 | Move some things in parse.y so that TK_COLUMN and TK_AGG_COLUMN are assigned the same values as they are on trunk for a very small speedup. check-in: d26fdfa3 user: dan tags: nulls-last | |
| 17:09 | Revise the VDBE comments for NULL-scan so that they also work make sense when reading a NULLS FIRST plan. check-in: bfe79378 user: drh tags: nulls-last | |
| 17:00 | Additional simplifications of the WHERE loop code generator logic for NULLS LAST. check-in: 1383680d user: drh tags: nulls-last | |
Changes
Changes to src/wherecode.c.
1687 1687 ** so no further seeking is needed */ 1688 1688 }else{ 1689 1689 if( pLoop->wsFlags & WHERE_IN_EARLYOUT ){ 1690 1690 sqlite3VdbeAddOp1(v, OP_SeekHit, iIdxCur); 1691 1691 } 1692 1692 if( regBignull ){ 1693 1693 sqlite3VdbeAddOp2(v, OP_Integer, 1, regBignull); 1694 - VdbeComment((v, "NULL-scan needed flag")); 1694 + VdbeComment((v, "NULL-scan pass ctr")); 1695 1695 } 1696 1696 1697 1697 op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev]; 1698 1698 assert( op!=0 ); 1699 1699 sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint); 1700 1700 VdbeCoverage(v); 1701 1701 VdbeCoverageIf(v, op==OP_Rewind); testcase( op==OP_Rewind ); ................................................................................ 1765 1765 pLevel->p2 = sqlite3VdbeCurrentAddr(v); 1766 1766 1767 1767 /* Check if the index cursor is past the end of the range. */ 1768 1768 if( nConstraint ){ 1769 1769 if( regBignull ){ 1770 1770 /* Except, skip the end-of-range check while doing the NULL-scan */ 1771 1771 sqlite3VdbeAddOp2(v, OP_IfNot, regBignull, sqlite3VdbeCurrentAddr(v)+3); 1772 - VdbeComment((v, "If NULL-scan active")); 1772 + VdbeComment((v, "If NULL-scan 2nd pass")); 1773 1773 VdbeCoverage(v); 1774 1774 } 1775 1775 op = aEndOp[bRev*2 + endEq]; 1776 1776 sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint); 1777 1777 testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT ); 1778 1778 testcase( op==OP_IdxGE ); VdbeCoverageIf(v, op==OP_IdxGE ); 1779 1779 testcase( op==OP_IdxLT ); VdbeCoverageIf(v, op==OP_IdxLT ); ................................................................................ 1782 1782 if( regBignull ){ 1783 1783 /* During a NULL-scan, check to see if we have reached the end of 1784 1784 ** the NULLs */ 1785 1785 assert( bSeekPastNull==!bStopAtNull ); 1786 1786 assert( bSeekPastNull+bStopAtNull==1 ); 1787 1787 assert( nConstraint+bSeekPastNull>0 ); 1788 1788 sqlite3VdbeAddOp2(v, OP_If, regBignull, sqlite3VdbeCurrentAddr(v)+2); 1789 - VdbeComment((v, "If NULL-scan pending")); 1789 + VdbeComment((v, "If NULL-scan 1st pass")); 1790 1790 VdbeCoverage(v); 1791 1791 op = aEndOp[bRev*2 + bSeekPastNull]; 1792 1792 sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, 1793 1793 nConstraint+bSeekPastNull); 1794 1794 testcase( op==OP_IdxGT ); VdbeCoverageIf(v, op==OP_IdxGT ); 1795 1795 testcase( op==OP_IdxGE ); VdbeCoverageIf(v, op==OP_IdxGE ); 1796 1796 testcase( op==OP_IdxLT ); VdbeCoverageIf(v, op==OP_IdxLT );