diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/btree.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/src/btree.c b/src/btree.c index d31d30c5e..d4cd0d020 100644 --- a/src/btree.c +++ b/src/btree.c @@ -8742,7 +8742,6 @@ static int anotherValidCursor(BtCursor *pCur){ */ static int balance(BtCursor *pCur){ int rc = SQLITE_OK; - const int nMin = pCur->pBt->usableSize * 2 / 3; u8 aBalanceQuickSpace[13]; u8 *pFree = 0; @@ -8754,7 +8753,11 @@ static int balance(BtCursor *pCur){ MemPage *pPage = pCur->pPage; if( NEVER(pPage->nFree<0) && btreeComputeFreeSpace(pPage) ) break; - if( pPage->nOverflow==0 && pPage->nFree<=nMin ){ + if( pPage->nOverflow==0 && pPage->nFree*3<=pCur->pBt->usableSize*2 ){ + /* No rebalance required as long as: + ** (1) There are no overflow cells + ** (2) The amount of free space on the page is less than 2/3rds of + ** the total usable space on the page. */ break; }else if( (iPage = pCur->iPage)==0 ){ if( pPage->nOverflow && (rc = anotherValidCursor(pCur))==SQLITE_OK ){ @@ -9568,7 +9571,15 @@ int sqlite3BtreeDelete(BtCursor *pCur, u8 flags){ ** been corrected, so be it. Otherwise, after balancing the leaf node, ** walk the cursor up the tree to the internal node and balance it as ** well. */ - rc = balance(pCur); + assert( pCur->pPage->nOverflow==0 ); + assert( pCur->pPage->nFree>=0 ); + if( pCur->pPage->nFree*3<=pCur->pBt->usableSize*2 ){ + /* Optimization: If the free space is less than 2/3rds of the page, + ** then balance() will always be a no-op. No need to invoke it. */ + rc = SQLITE_OK; + }else{ + rc = balance(pCur); + } if( rc==SQLITE_OK && pCur->iPage>iCellDepth ){ releasePageNotNull(pCur->pPage); pCur->iPage--; |