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| author | drh <> | 2022-07-25 20:21:57 +0000 |
|---|---|---|
| committer | drh <> | 2022-07-25 20:21:57 +0000 |
| commit | 47e2fe3ce78af0c2dd32a0e8f6e10d2211a932d2 (patch) | |
| tree | fe6c357a0c92a6a06beb3e7e490801ea98d7f647 /src/expr.c | |
| parent | 058e99502a70abb5e67bead9a4146f4523ff89d9 (diff) | |
| download | sqlite-47e2fe3ce78af0c2dd32a0e8f6e10d2211a932d2.tar.gz sqlite-47e2fe3ce78af0c2dd32a0e8f6e10d2211a932d2.zip | |
Performance optimization in computing the Expr.nHeight field.
FossilOrigin-Name: 1798ce97c8763d75315e1716d10f6c5be301042c174f41ee8c1fb8d9db99d52b
Diffstat (limited to 'src/expr.c')
| -rw-r--r-- | src/expr.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/src/expr.c b/src/expr.c index c383f6f65..44744524a 100644 --- a/src/expr.c +++ b/src/expr.c @@ -770,7 +770,9 @@ static void heightOfSelect(const Select *pSelect, int *pnHeight){ */ static void exprSetHeight(Expr *p){ int nHeight = p->pLeft ? p->pLeft->nHeight : 0; - if( p->pRight && p->pRight->nHeight>nHeight ) nHeight = p->pRight->nHeight; + if( NEVER(p->pRight) && p->pRight->nHeight>nHeight ){ + nHeight = p->pRight->nHeight; + } if( ExprUseXSelect(p) ){ heightOfSelect(p->x.pSelect, &nHeight); }else if( p->x.pList ){ @@ -913,15 +915,26 @@ void sqlite3ExprAttachSubtrees( sqlite3ExprDelete(db, pLeft); sqlite3ExprDelete(db, pRight); }else{ + assert( ExprUseXList(pRoot) ); + assert( pRoot->x.pSelect==0 ); if( pRight ){ pRoot->pRight = pRight; pRoot->flags |= EP_Propagate & pRight->flags; +#if SQLITE_MAX_EXPR_DEPTH>0 + pRoot->nHeight = pRight->nHeight+1; + }else{ + pRoot->nHeight = 1; +#endif } if( pLeft ){ pRoot->pLeft = pLeft; pRoot->flags |= EP_Propagate & pLeft->flags; +#if SQLITE_MAX_EXPR_DEPTH>0 + if( pLeft->nHeight>=pRoot->nHeight ){ + pRoot->nHeight = pLeft->nHeight+1; + } +#endif } - exprSetHeight(pRoot); } } |