- Unify EXPLAIN printout for <subqueryN> tables with regular tables
- Update test results for <subqueryN> tables:
s/unique_key/distinct_key/g
s/1.0/100.0/ for "filtered" column
- Make join buffering take into account that join_tabs are not a
single linear array anymore
- Remove outer join + SJ-Materialization crash (OJ+SJ the processing
is most likely still incorrect)
- Change "SUBQUERY#n" to "<subquery{n}>" in EXPLAIN output. We need to it to be
lowercase so that EXPLAIN results do not differ in case between systems with
case-sensitive and case-insensitive filesystems.
- Remove garbage comments, add better comments.
- Code cleanu.
- Make MWL#90 code require @@optimizer_switch='semijoin=on'
- Update test results with the above
- Fork subselect_mat.test - we want to check both semi-join materialization,
which now has broader scope and non-semijoin materialization.
- Add Item_in_subselect::get_identifier() that returns subquery's id
- Change select_describe() to produce output in new format
- Update test results (checked)
mysql-test/r/union.result:
Update test results (checked, it should be "DEPENDENT SUBQUERY" as it will actually run subquery's join multiple times. There is no reason to do that but executor will still do it)
Fix two problems:
1. Let optimize_semijoin_nests() reset sj_nest->sjmat_info irrespectively
of value of optimizer_flag. We need this in case somebody has turned optimization
off between reexecutions of the same statement.
2. Do not pull out constant tables out of semi-join nests. The problem is that pullout
operation is not undoable, and if a table is constant because it is 1/0-row table it
may cease to be constant on the next execution. Note that tables that are constant
because of possible eq_ref(const) access will still be pulled out as they are
considered functionally-dependent.
BUG#50019: Wrong result for IN-subquery with materialization
- Fix equality substitution in presense of semi-join materialization, lookup and scan variants
(started off from fix by Evgen Potemkin, then modified it to work in all cases)
tmp_table_size can now be set to 0 (to disable in memory internal temp tables)
Improved speed for internal Maria temp tables:
- Don't use packed keys, except with long text fields.
- Don't copy key all accessed pages during key search.
Some new benchmark tests to sql-bench (for group by)
BUILD/compile-pentium64-gcov:
Update script to use same pentium_config flags as other tests
BUILD/compile-pentium64-gprof:
Update script to use same pentium_config flags as other tests
include/my_sys.h:
Added count of my_sync calls
mysql-test/r/variables.result:
tmp_table_size can now be set to 0
sql-bench/test-select.sh:
Added some new test for GROUP BY on a not key field and group by with different order by
sql/mysqld.cc:
Added count of my_sync calls
tmp_table_size can now be set to 0 (to disable in memory internal temp tables)
sql/sql_select.cc:
If tmp_table_size is 0, don't use in memory temp tables (good for benchmarking MyISAM/Maria temp tables)
Don't pack keys for Maria tables; The 8K page size makes packed keys too slow for temp tables.
storage/maria/ma_key_recover.h:
Moved definition to maria_def.h
storage/maria/ma_page.c:
Moved code used to simplify comparing of identical Maria tables to own function (page_cleanup())
Fixed that one can read a page with a read lock.
storage/maria/ma_rkey.c:
For not exact key reads, cache the page where we found key (to speed up future read-next/read-prev calls)
storage/maria/ma_search.c:
Moved code to cache last key page to separate function.
Instead of copying pages, only get a link to the page. This notable speeds up key searches on bigger tables.
storage/maria/ma_write.c:
Added comment
storage/maria/maria_def.h:
Moved page_cleanup() to separate function.
- The problem was that DuplicateWeedout strategy setup code wasn't aware of the
fact that join buffering will be used and applied optimization that doesn't work
together with join buffering. Fixed by making DuplicateWeedout setup code to have
a pessimistic check about whether there is a chance that join buffering will be
used.
- Make JOIN_CACHE_BKA::init() correctly process Copy_field elements that denote saving
current rowids in the join buffer.
mysql-test/r/subselect_sj2.result:
Update test results
mysql-test/r/subselect_sj2_jcl6.result:
Update test results
mysql-test/r/subselect_sj_jcl6.result:
Testcase
mysql-test/t/subselect_sj2.test:
Update test results
mysql-test/t/subselect_sj_jcl6.test:
Testcase
sql/opt_subselect.cc:
- The problem was that DuplicateWeedout strategy setup code wasn't aware of the
fact that join buffering will be used and applied optimization that doesn't work
together with join buffering. Fixed by making DuplicateWeedout setup code to have
a pessimistic check about whether there is a chance that join buffering will be
used.
sql/sql_join_cache.cc:
Make JOIN_CACHE_BKA::init() correctly process Copy_field elements that denote saving current rowids in the join buffer.
sql/sql_select.cc:
Added a question note
Save no-records constant tables in JOIN::const_table_map before we invoke
eliminate_tables(). Failure to do so caused crash when the same table was
marked as constant two times
mysql-test/r/table_elim.result:
LPBUG#524025 Running RQG outer_join test leads to crash
- Testcase
mysql-test/t/table_elim.test:
LPBUG#524025 Running RQG outer_join test leads to crash
- Testcase
sql/sql_select.cc:
LPBUG#524025 Running RQG outer_join test leads to crash
Save no-records constant tables in JOIN::const_table_map before we invoke eliminate_tables(). Failure to do so caused crash when the same table was marked as constant two times.
This patch implements correct NULL semantics for materialized subquery execution.
The implementation has the following properties and main limitations:
- It passes all query result tests, but fails a number of EXPLAIN tests because of
changed plans.
- The EXPLAIN output for partial matching is not decided yet.
- It works only when all necessary indexes fit into main memory. Notice that these
are not the general B-tree/Hash indexes, but instead much more compact ones,
therefore this limitation may not be a problem in many practical cases.
- It doesn't contain specialized tests.
- In several places the implementation uses methods that are modified copies of
other similar methods. These cases need to be refactored to avoid code duplication.
- Add a test if the predicate is top-level just before deciding on partial matching.
If it is top-level, use a more efficient exec method (index lookup).
- Add sorting of indexes according to their selectivity. The code is almost there.
- Needs more comments, and to sync existing ones with the implementation.
sql/item_cmpfunc.h:
Expose the Arg_comparator of a comparison predicate. This makes it possible to
directly get the comparison result {-1,0,1}, which is not possible through the
val_XXX() methods which "fold" such results into a boolean.
sql/item_subselect.cc:
The core of the implementation of MWL#68.
sql/item_subselect.h:
The core of the implementation of MWL#68.
sql/opt_subselect.cc:
Removed the limitation for materialized subquery execution that it is applicable only
for top-level predicates.
sql/sql_class.cc:
New class select_materialize_with_stats that collects data statistics about
the data being inserted into the target table.
sql/sql_class.h:
New class select_materialize_with_stats that collects data statistics about
the data being inserted into the target table.
sql/sql_select.cc:
- more complete initialization of the TABLE object of a temp table.
- call setup_subquery_materialization at one more exit point.
fulltext search and row op.
The search for fulltext indexes is searching for some special
predicate layouts. While doing so it's not checking for the number
of columns of the expressions it tries to calculate.
And since row expressions can't return a single scalar value there
was a crash.
Fixed by checking if the expressions are scalar (in addition to
being constant) before calling Item::val_xxx() methods.
column is used for ORDER BY
Problem: filesort isn't meant for null length sort data
(e.g. char(0)), that leads to a server crash.
Fix: disregard sort order if sort data record length is 0 (nothing
to sort).
mysql-test/r/select.result:
Fix for bug#49897: crash in ptr_compare when char(0) NOT NULL
column is used for ORDER BY
- test result.
mysql-test/t/select.test:
Fix for bug#49897: crash in ptr_compare when char(0) NOT NULL
column is used for ORDER BY
- test case.
sql/filesort.cc:
Fix for bug#49897: crash in ptr_compare when char(0) NOT NULL
column is used for ORDER BY
- assert added as filesort cannot handle null length sort data.
sql/sql_select.cc:
Fix for bug#49897: crash in ptr_compare when char(0) NOT NULL
column is used for ORDER BY
- don't sort null length data e.g. in case of ORDER BY CHAR(0).
