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Whenever a generated column is used, assume that all columns are used.

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FossilOrigin-Name: 6601da58032d18ae00b466c0f2077fb2b1ecd84225b56e1787724bea478eedc9
This commit is contained in:
drh
2019-11-21 19:37:00 +00:00
parent 57f7ece784
commit 522ebfa7ce
4 changed files with 33 additions and 14 deletions
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20
src/resolve.c
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@@ -551,9 +551,18 @@ static int lookupName(
/* If a column from a table in pSrcList is referenced, then record
** this fact in the pSrcList.a[].colUsed bitmask. Column 0 causes
** bit 0 to be set. Column 1 sets bit 1. And so forth. If the
** column number is greater than the number of bits in the bitmask
** then set the high-order bit of the bitmask.
** bit 0 to be set. Column 1 sets bit 1. And so forth.
**
** The colUsed mask is an optimization used to help determine if an
** index is a covering index. The correct answer is still obtained
** if the mask contains extra bits. But omitting bits from the mask
** might result in an incorrect answer.
**
** The high-order bit of the mask is a "we-use-them-all" bit.
** If the column number is greater than the number of bits in the bitmask
** then set the high-order bit of the bitmask. Also set the high-order
** bit if the column is a generated column, as that adds dependencies
** that are difficult to track, so we assume that all columns are used.
*/
if( pExpr->iColumn>=0 && pMatch!=0 ){
int n = pExpr->iColumn;
@@ -561,7 +570,12 @@ static int lookupName(
if( n>=BMS ){
n = BMS-1;
}
assert( pExpr->y.pTab!=0 );
assert( pMatch->iCursor==pExpr->iTable );
if( pExpr->y.pTab->tabFlags & TF_HasGenerated ){
Column *pCol = pExpr->y.pTab->aCol + pExpr->iColumn;
if( pCol->colFlags & COLFLAG_GENERATED ) n = BMS-1;
}
pMatch->colUsed |= ((Bitmask)1)<<n;
}