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Overview
| Comment: | A better implementation of the moveto-neighbor optimization that checks for nearby rows on adjacent pages. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | btree-moveto-neighbor |
| Files: | files | file ages | folders |
| SHA1: |
2c4ecb85a475b9063aa8a3bb517ac181 |
| User & Date: | drh 2017-01-21 21:47:54 |
Context
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2017-01-23
| ||
| 16:56 | Optimization: Try to avoid unnecessary btree searching when repositioning a cursor to the next row. check-in: ee793d30 user: drh tags: trunk | |
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2017-01-21
| ||
| 21:47 | A better implementation of the moveto-neighbor optimization that checks for nearby rows on adjacent pages. Closed-Leaf check-in: 2c4ecb85 user: drh tags: btree-moveto-neighbor | |
| 16:54 | B-tree optimization: When seeking on a rowid table that has already been positioned, check to see if the new row happens to be the next row on the same leaf page. That is a reasonably common case, and if it is true it avoids a full binary search. check-in: 8e5cfb20 user: drh tags: btree-moveto-neighbor | |
Changes
Changes to src/btree.c.
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return SQLITE_OK;
}
if( pCur->info.nKey<intKey ){
if( (pCur->curFlags & BTCF_AtLast)!=0 ){
*pRes = -1;
return SQLITE_OK;
}
if( pCur->aiIdx[pCur->iPage]+1<pCur->apPage[pCur->iPage]->nCell ){
pCur->aiIdx[pCur->iPage]++;
pCur->info.nSize = 0;
pCur->curFlags &= ~(BTCF_ValidNKey|BTCF_ValidOvfl);
getCellInfo(pCur);
if( pCur->info.nKey==intKey ){
*pRes = 0;
return SQLITE_OK;
}
}
}
}
if( pIdxKey ){
xRecordCompare = sqlite3VdbeFindCompare(pIdxKey);
|
| | | | > > > > > | | < | > |
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return SQLITE_OK;
}
if( pCur->info.nKey<intKey ){
if( (pCur->curFlags & BTCF_AtLast)!=0 ){
*pRes = -1;
return SQLITE_OK;
}
/* If the requested key is one more than the previous key, then
** try to get there using sqlite3BtreeNext() rather than a full
** binary search. This is an optimization only. The correct answer
** is still obtained without this ase, only a little more slowely */
if( pCur->info.nKey+1==intKey && !pCur->skipNext ){
*pRes = 0;
rc = sqlite3BtreeNext(pCur, pRes);
if( rc ) return rc;
if( *pRes==0 ){
getCellInfo(pCur);
if( pCur->info.nKey==intKey ){
return SQLITE_OK;
}
}
}
}
}
if( pIdxKey ){
xRecordCompare = sqlite3VdbeFindCompare(pIdxKey);
|