| Bug #37208 | Wrong query result for big innodb table when index condition pushdown is used | ||
|---|---|---|---|
| Submitted: | 4 Jun 2008 22:19 | Modified: | 18 Dec 2009 12:18 |
| Reporter: | Sergey Petrunya | Email Updates: | |
| Status: | Duplicate | Impact on me: | |
| Category: | MySQL Server: Optimizer | Severity: | S3 (Non-critical) |
| Version: | 6.0 | OS: | Any |
| Assigned to: | Assigned Account | CPU Architecture: | Any |
| Tags: | index_condition_pushdown, optimizer_switch | ||
[4 Jun 2008 22:21]
Sergey Petrunya
Here's a patch that fixes the problem. The testcase part is difficult because in order to repeat one needs to scan a certain number of records and InnoDB's record prefetch buffer must hold certain data.
===== row0sel.c 1.127 vs edited =====
--- 1.127/storage/innobase/row/row0sel.c 2008-03-27 02:56:11 +01:00
+++ edited/row0sel.c 2008-06-01 04:43:15 +02:00
@@ -3112,8 +3112,12 @@ row_sel_push_cache_row_for_mysql(
if (templ->mysql_null_bit_mask) {
offs= templ->mysql_null_byte_offset;
- *(prebuilt->fetch_cache[prebuilt->n_fetch_cached] + offs) ^=
- (*(remainder_buf + offs) & templ->mysql_null_bit_mask);
+ if (*(remainder_buf + offs) & templ->mysql_null_bit_mask)
+ *(prebuilt->fetch_cache[prebuilt->n_fetch_cached] + offs) |=
+ /* (*(remainder_buf + offs) &*/( templ->mysql_null_bit_mask);
+ else
+ *(prebuilt->fetch_cache[prebuilt->n_fetch_cached] + offs) &=
+ ~templ->mysql_null_bit_mask;
}
offs= templ->mysql_col_offset;
memcpy(prebuilt->fetch_cache[prebuilt->n_fetch_cached] + offs,
[8 Oct 2009 11:58]
Guilhem Bichot
trusting Sergey's assessment, I remove tag engine_condition_pushdown as bug is said to be in index condition pushdown.
[1 Dec 2009 10:44]
Sergey Petrunya
The testcase that was missing in this bug can be found in BUG#43249.
[2 Dec 2009 9:46]
Manyi Lu
Contribution from sca@askmonty.org 11/23/09: http://lists.mysql.com/internals/37545
Description: Running this query on DBT-3 scale=1 loaded in innodb may produces wrong query result: select count(*) from part, lineitem, partsupp where l_partkey=p_partkey and p_retailprice>1525 and l_discount>0.04 and ps_partkey=p_partkey and ps_supplycost>520 ; The problem occurs only when the query uses index condition pushdown. How to repeat: See above.