From 5f83a7fbf8df25b444eedbc88925fe8912b12fd2 Mon Sep 17 00:00:00 2001 From: Aditya A Date: Tue, 5 Nov 2013 19:25:26 +0530 Subject: Bug#17588348: INDEX MERGE USED ON PARTITIONED TABLE CAN RETURN WRONG RESULT SET PROBLEM ------- In ha_partition::cmp_ref() we were only calling the underlying cmp_ref() of storage engine if the records are in the same partiton,else we sort by partition and returns the result.But the index merge intersect algorithm expects first to sort by row-id first and then by partition id. FIX --- Compare the refernces first using storage engine cmp_ref and then if references are equal(only happens if non clustered index is used) then sort it by partition id. [Approved by Mattiasj #rb3755] - --- sql/ha_partition.cc | 24 +++++++++++++++++------- 1 file changed, 17 insertions(+), 7 deletions(-) (limited to 'sql/ha_partition.cc') diff --git a/sql/ha_partition.cc b/sql/ha_partition.cc index 507f202e349..bf4ba5ed765 100644 --- a/sql/ha_partition.cc +++ b/sql/ha_partition.cc @@ -7485,19 +7485,29 @@ uint ha_partition::min_record_length(uint options) const int ha_partition::cmp_ref(const uchar *ref1, const uchar *ref2) { - uint part_id; + int cmp; my_ptrdiff_t diff1, diff2; - handler *file; DBUG_ENTER("ha_partition::cmp_ref"); + cmp = m_file[0]->cmp_ref((ref1 + PARTITION_BYTES_IN_POS), + (ref2 + PARTITION_BYTES_IN_POS)); + if (cmp) + DBUG_RETURN(cmp); + if ((ref1[0] == ref2[0]) && (ref1[1] == ref2[1])) { - part_id= uint2korr(ref1); - file= m_file[part_id]; - DBUG_ASSERT(part_id < m_tot_parts); - DBUG_RETURN(file->cmp_ref((ref1 + PARTITION_BYTES_IN_POS), - (ref2 + PARTITION_BYTES_IN_POS))); + /* This means that the references are same and are in same partition.*/ + DBUG_RETURN(0); } + + /* + In Innodb we compare with either primary key value or global DB_ROW_ID so + it is not possible that the two references are equal and are in different + partitions, but in myisam it is possible since we are comparing offsets. + Remove this assert if DB_ROW_ID is changed to be per partition. + */ + DBUG_ASSERT(!m_innodb); + diff1= ref2[1] - ref1[1]; diff2= ref2[0] - ref1[0]; if (diff1 > 0) -- cgit v1.2.1