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author | Arun Kuruvila <arun.kuruvila@oracle.com> | 2013-12-30 11:39:55 +0530 |
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committer | Arun Kuruvila <arun.kuruvila@oracle.com> | 2013-12-30 11:39:55 +0530 |
commit | 51519388f17c213e5247c17cdecf7a0d5ec3ac3a (patch) | |
tree | 20e07dc02e20e4b09464bf1a22205d88d556c228 /storage/ndb/src/cw/test/socketclient/socketClientTest.cpp | |
parent | 96ae8409e1d8a67b4011b55a7b2ec5ae0342f91a (diff) | |
download | mariadb-git-51519388f17c213e5247c17cdecf7a0d5ec3ac3a.tar.gz |
Bug #16324629 : SERVER CRASHES ON UPDATE/JOIN FEDERATED +
LOCAL TABLE WHEN ONLY 1 LOCAL ROW
Description: When updating a federated table with UPDATE...
JOIN, the server consistently crashes with Signal 11 when
only 1 row exists in the local table involved in the join
and that 1 row can be joined with a row in the federated
table.
Analysis: Interaction between the federated engine and the
optimizer results in the crash. In our scenario, ie, local
table having only one row, the program is following a
different path because the table is treated as a constant
table by the join optimizer. So in this scenario
"index_read()" is happening in the prepare phase,
since optimizer plan is different for constant table joins.
In this case, "index_read_idx_map()" (inside handler.cc) is
calling "index_read()" and inside "index_read()", matching
rows are fetched and "stored_result" gets populated by
calling "store_result()". And just after "index_read()",
"index_end()" function is called. And in the "index_end()",
its freeing the "stored_result" by calling "free_result()".
So when it reaches the execution phase, in "position()"
function, we are getting assertion at
"DBUG_ASSERT(stored_result);". In all other scenarios (ie,
table with more than 1 row), optimizer plan is different
and "index_read()" is happening in the execution phase.
Fix: So my fix is to have a separate ha_federated member
function for "index_read_idx_map()" which will handle
federated engine separately. So that position() will be
called before index_end() call in constant table scenario.
Diffstat (limited to 'storage/ndb/src/cw/test/socketclient/socketClientTest.cpp')
0 files changed, 0 insertions, 0 deletions