with open HANDLER
This patch changes the code for table renames to not drop metadata
locks. Since table renames are done as a part of ALTER DATABASE ...
UPGRADE, dropping metadata locks in the middle of execution can
result in wrong binlog order since it means that no locks are held
when the binlog is written to.
The RENAME TABLE statement is unafffected since it auto commits and
therefore already drops metadata locks at the end of execution.
This patch also reverts the regression test for Bug#48940 back to
its original version. The test was temporarily changed due to the
issue mentioned above.
with open HANDLER
Fixes a problem with schema.test visible using embedded server.
The HANDLER was not closed which caused the test to hang.
The problem was not visible if the test was run on a normal server
as the the handler there was implicitly closed by DATABASE DDL
statements doing Events::drop_schema_events().
DATABASE with open HANDLER"
Remove LOCK_create_db, database name locks, and use metadata locks instead.
This exposes CREATE/DROP/ALTER DATABASE statements to the graph-based
deadlock detector in MDL, and paves the way for a safe, deadlock-free
implementation of RENAME DATABASE.
Database DDL statements will now take exclusive metadata locks on
the database name, while table/view/routine DDL statements take
intention exclusive locks on the database name. This prevents race
conditions between database DDL and table/view/routine DDL.
(e.g. DROP DATABASE with concurrent CREATE/ALTER/DROP TABLE)
By adding database name locks, this patch implements
WL#4450 "DDL locking: CREATE/DROP DATABASE must use database locks" and
WL#4985 "DDL locking: namespace/hierarchical locks".
The patch also changes code to use init_one_table() where appropriate.
The new lock_table_names() function requires TABLE_LIST::db_length to
be set correctly, and this is taken care of by init_one_table().
This patch also adds a simple template to help work with
the mysys HASH data structure.
Most of the patch was written by Konstantin Osipov.
This was a deadlock between LOCK TABLES/CREATE DATABASE in one connection
and DROP DATABASE in another. It only happened if the table locked by
LOCK TABLES was in the database to be dropped. The deadlock is similar
to the one in Bug#48940, but with LOCK TABLES instead of an active
transaction.
The order of events needed to trigger the deadlock was:
1) Connection 1 locks table db1.t1 using LOCK TABLES. It will now
have a metadata lock on the table name.
2) Connection 2 issues DROP DATABASE db1. This will wait inside
the MDL subsystem for the lock on db1.t1 to go away. While waiting, it
will hold the LOCK_mysql_create_db mutex.
3) Connection 1 issues CREATE DATABASE (database name irrelevant).
This will hang trying to lock the same mutex. Since this is the connection
holding the metadata lock blocking Connection 2, we have a deadlock.
This deadlock would also happen for earlier trees without MDL, but
there DROP DATABASE would wait for a table to be removed from the
table definition cache.
This patch fixes the problem by prohibiting CREATE DATABASE in LOCK TABLES
mode. In the example above, this prevents Connection 1 from hanging trying
to get the LOCK_mysql_create_db mutex. Note that other commands that use
LOCK_mysql_create_db (ALTER/DROP DATABASE) are already prohibited in
LOCK TABLES mode.
Incompatible change: CREATE DATABASE is now disallowed in LOCK TABLES mode.
Test case added to schema.test.
mysql-test/t/drop.test:
Updates the test for Bug#21216 by swapping the order of CREATE DATABASE
and LOCK TABLES. This is now needed as CREATE DATABASE is prohibited in
LOCK TABLES mode.
mysql-test/t/schema.test:
Test case for Bug#49988 added.
Also fixes a problem with the test for Bug#48940 where the result
would differ for embedded server.
This deadlock would occur between two connections A and B if statements
where executed in the following way:
1) Connection A executes a DML statement against table s1.t1 with
autocommit off. This causes a shared metadata lock on s1.t1 to be
acquired. (With autocommit on, the metadata lock will be dropped once
the statment completes and the deadlock will not occour.)
2) Connection B tries to DROP DATABASE s1. This will block against the
metadata lock connection A holds on s1.t1. While blocking, connection B
will hold the LOCK_mysql_create_db mutex.
3) Connection A tries to ALTER DATABASE s1. This will block when trying
to get LOCK_mysql_create_db mutex held by connection B.
4) Deadlock between DROP DATABASE and ALTER DATABASE (which has autocommit
off).
If Connection A used an explicitly started transaction rather than having
autocommit off, this deadlock did not happen as ALTER DATABASE is
disallowed inside transactions.
This patch fixes the problem by changing ALTER DATABASE to cause an
implicit commit before executing. This will cause the metadata
lock on s1.t1 to be dropped, allowing DROP DATABASE to proceed.
This will in turn cause the LOCK_mysql_create_db mutex to be unlocked,
allowing ALTER DATABASE to proceed.
Note that SQL commands other than ALTER DATABASE that also use
LOCK_mysql_create_db, already cause an implicit commit.
Incompatible change: ALTER DATABASE (and its synonym ALTER SCHEMA)
now cause an implicit commit. This must be reflected in the
documentation.
Test case added to schema.test.
sql/sql_parse.cc:
Added CF_AUTO_COMMIT_TRANS to SQLCOM_ALTER_DB.
Removed thd->active_transaction() checks from SQLCOM_DROP_DB,
SQLCOM_ALTER_DB_UPGRADE and SQLCOM_ALTER_DB as these statements
cause an implicit commit.
Moved .progress files into the log directory
Moved 'cluster' database tables into the MySQL database, to not have 'cluster' beeing a reserved database name
Fixed bug where mysqld got a core dump when trying to use a table created by MySQL 3.23
Fixed some compiler warnings
Fixed small memory leak in libmysql
Note that this doesn't changeset doesn't include the new mysqldump.c code required to run some tests. This will be added when I merge 5.0 to 5.1
client/client_priv.h:
Added OPT_DEBUG_INFO and OPT_COLUMN_TYPES
client/mysql.cc:
Split --debug-info into --debug-info and --column-type-info
client/mysql_upgrade.c:
Give only error info at end if using --debug-info
client/mysqladmin.cc:
Added --debug-info to detect memory leaks in mysqltest
client/mysqlbinlog.cc:
Added --debug-info to detect memory leaks in mysqltest
client/mysqlcheck.c:
Added --debug-info to detect memory leaks in mysqltest
client/mysqlimport.c:
Added --debug-info to detect memory leaks in mysqltest
client/mysqlshow.c:
Added --debug-info to detect memory leaks in mysqltest
client/mysqltest.c:
Added --debug-info to detect memory leaks in mysqltest
Added option --logdir to force .progress files in a specific directory
libmysql/libmysql.c:
Fixed memory leak
mysql-test/include/ndb_setup_slave.inc:
Moved cluster tables under 'mysql'
mysql-test/include/query_cache.inc:
Added more tests for query cache
mysql-test/lib/init_db.sql:
Move cluster.binlog_index -> mysql.binlog_index
mysql-test/lib/mtr_report.pl:
Find memory leaks
mysql-test/mysql-test-run-shell.sh:
Added --debug-info to programs to detect memory leaks
mysql-test/mysql-test-run.pl:
Added --debug-info to programs to detect memory leaks
Force log files to var/log
cluster tables moved under 'mysql'
mysql-test/r/cache_innodb.result:
New query cache test with innodb
mysql-test/r/connect.result:
binlog_index is now in mysql
mysql-test/r/drop.result:
Removed 'cluster' database
mysql-test/r/information_schema.result:
Removed 'cluster' database
mysql-test/r/mysqlcheck.result:
cluster.binlog_index -> mysql.binlog_index
mysql-test/r/ndb_binlog_basic.result:
cluster.binlog_index -> mysql.binlog_index
mysql-test/r/ndb_binlog_ddl_multi.result:
cluster -> mysql
mysql-test/r/ndb_binlog_discover.result:
cluster -> mysql
mysql-test/r/ndb_binlog_multi.result:
cluster -> mysql
mysql-test/r/ndb_restore_compat.result:
cluster -> mysql
mysql-test/r/ps_1general.result:
Removed cluster database
mysql-test/r/rpl_create_database.result:
Removed cluster database
mysql-test/r/rpl_load_from_master.result:
Removed cluster database
mysql-test/r/rpl_loaddata_m.result:
Removed cluster database
mysql-test/r/rpl_ndb_bank.result:
cluster -> mysql
mysql-test/r/rpl_ndb_dd_advance.result:
cluster -> mysql
mysql-test/r/rpl_ndb_dd_basic.result:
cluster -> mysql
mysql-test/r/rpl_ndb_idempotent.result:
cluster -> mysql
mysql-test/r/rpl_ndb_log.result:
cluster -> mysql
mysql-test/r/rpl_ndb_multi.result:
cluster -> mysql
mysql-test/r/rpl_ndb_sync.result:
cluster -> mysql
mysql-test/r/rpl_row_basic_11bugs.result:
Removed cluster database
mysql-test/r/rpl_truncate_7ndb.result:
Position have changed
mysql-test/r/rpl_truncate_7ndb_2.result:
cluster -> mysql
mysql-test/r/schema.result:
Removed cluster database
mysql-test/r/show_check.result:
Removed cluster database
mysql-test/r/system_mysql_db.result:
binlog_index moved under mysql
mysql-test/r/upgrade.result:
More tests
mysql-test/t/information_schema.test:
cluster -> mysql
mysql-test/t/mysqldump.test:
More test to detect memory leaks
mysql-test/t/ndb_binlog_basic.test:
cluster -> mysql
mysql-test/t/ndb_binlog_multi.test:
cluster -> mysql
mysql-test/t/ndb_restore_compat.test:
cluster -> mysql
mysql-test/t/rpl_ndb_bank.test:
cluster -> mysql
mysql-test/t/rpl_ndb_dd_advance.test:
cluster -> mysql
mysql-test/t/rpl_ndb_idempotent.test:
cluster -> mysql
mysql-test/t/rpl_ndb_multi.test:
cluster -> mysql
mysql-test/t/rpl_ndb_sync.test:
cluster -> mysql
mysql-test/t/system_mysql_db_fix.test:
Drop also binlog_index
mysql-test/t/upgrade.test:
Check that tables created with 3.23 works
mysys/my_error.c:
Remove all registered errors (to avoid memory leaks)
mysys/my_init.c:
call my_error_unregister_all() to avoid some possible memory leaks
mysys/mysys_priv.h:
Added prototype
scripts/mysql_create_system_tables.sh:
cluster -> mysql
scripts/mysql_fix_privilege_tables.sql:
Changed -- to #
Create binlog_index table if it dosesn't exist
sql/field.cc:
Made offset() inline
sql/field.h:
Changed prototype of offset() to not make it depending on TABLE structure
sql/field_conv.cc:
Removed some usage of current_thd
sql/ha_ndbcluster_tables.h:
cluster -> mysql
sql/item_sum.cc:
Usage of new 'offset' parameters
sql/key.cc:
Changed 'find_ref_key' to not be dependent on field->table
(This fixed a crash when using a table created in MySQL 3.23)
sql/mysql_priv.h:
Changed find_ref_key() to not use field->table
sql/mysqld.cc:
Fix that plugin_init() works properly on bootstrap
(Previously we got warnings from plugin_init)
sql/sql_class.cc:
new 'field->offset()'
sql/sql_select.cc:
New field->offset()
sql/table.cc:
We don't need field->table to be set in find_ref_key() or find_field() anymore.
storage/archive/ha_archive.cc:
New field->offset()
storage/federated/ha_federated.cc:
New field->offset()
storage/innobase/handler/ha_innodb.cc:
Fixed compiler warnings
storage/myisam/ha_myisam.cc:
Fixed compiler warnings (Wrong paramter to sprintf())
New field->offset()
storage/myisam/ha_myisam.h:
Fixed wrong type of table_flags
storage/ndb/tools/restore/Restore.cpp:
Fixed compiler warning
mysql-test/r/1st.result:
New BitKeeper file ``mysql-test/r/1st.result''
mysql-test/std_data/old_table-323.frm:
New BitKeeper file ``mysql-test/std_data/old_table-323.frm''
mysql-test/t/1st.test:
New BitKeeper file ``mysql-test/t/1st.test''
mysql-test/include/have_ndb_extra.inc:
New BitKeeper file ``mysql-test/include/have_ndb_extra.inc''
mysql-test/include/not_ndb.inc:
New BitKeeper file ``mysql-test/include/not_ndb.inc''
mysql-test/r/have_ndb_extra.require:
New BitKeeper file ``mysql-test/r/have_ndb_extra.require''
mysql-test/r/ndb_alter_table_row.result:
New BitKeeper file ``mysql-test/r/ndb_alter_table_row.result''
mysql-test/r/ndb_alter_table_stm.result:
New BitKeeper file ``mysql-test/r/ndb_alter_table_stm.result''
mysql-test/r/ndb_binlog_basic.result:
New BitKeeper file ``mysql-test/r/ndb_binlog_basic.result''
mysql-test/r/ndb_binlog_multi.result:
New BitKeeper file ``mysql-test/r/ndb_binlog_multi.result''
mysql-test/r/ndb_multi_row.result:
New BitKeeper file ``mysql-test/r/ndb_multi_row.result''
mysql-test/r/not_ndb.require:
New BitKeeper file ``mysql-test/r/not_ndb.require''
mysql-test/r/rpl_ndb_bank.result:
New BitKeeper file ``mysql-test/r/rpl_ndb_bank.result''
mysql-test/r/rpl_ndb_basic.result:
New BitKeeper file ``mysql-test/r/rpl_ndb_basic.result''
mysql-test/r/rpl_ndb_disk.result:
New BitKeeper file ``mysql-test/r/rpl_ndb_disk.result''
mysql-test/r/rpl_ndb_idempotent.result:
New BitKeeper file ``mysql-test/r/rpl_ndb_idempotent.result''
mysql-test/r/rpl_ndb_load.result:
New BitKeeper file ``mysql-test/r/rpl_ndb_load.result''
mysql-test/r/rpl_ndb_multi.result:
New BitKeeper file ``mysql-test/r/rpl_ndb_multi.result''
mysql-test/r/rpl_ndb_sync.result:
New BitKeeper file ``mysql-test/r/rpl_ndb_sync.result''
mysql-test/r/rpl_row_basic_7ndb.result:
New BitKeeper file ``mysql-test/r/rpl_row_basic_7ndb.result''
mysql-test/t/ndb_alter_table_row.test:
New BitKeeper file ``mysql-test/t/ndb_alter_table_row.test''
mysql-test/t/ndb_alter_table_stm.test:
New BitKeeper file ``mysql-test/t/ndb_alter_table_stm.test''
mysql-test/t/ndb_binlog_basic.test:
New BitKeeper file ``mysql-test/t/ndb_binlog_basic.test''
mysql-test/t/ndb_binlog_multi.test:
New BitKeeper file ``mysql-test/t/ndb_binlog_multi.test''
mysql-test/t/ndb_multi_row.test:
New BitKeeper file ``mysql-test/t/ndb_multi_row.test''
mysql-test/t/rpl_ndb_bank.test:
New BitKeeper file ``mysql-test/t/rpl_ndb_bank.test''
mysql-test/t/rpl_ndb_basic.test:
New BitKeeper file ``mysql-test/t/rpl_ndb_basic.test''
mysql-test/t/rpl_ndb_disk.test:
New BitKeeper file ``mysql-test/t/rpl_ndb_disk.test''
mysql-test/t/rpl_ndb_idempotent.test:
New BitKeeper file ``mysql-test/t/rpl_ndb_idempotent.test''
mysql-test/t/rpl_ndb_load.test:
New BitKeeper file ``mysql-test/t/rpl_ndb_load.test''
mysql-test/t/rpl_ndb_multi.test:
New BitKeeper file ``mysql-test/t/rpl_ndb_multi.test''
mysql-test/t/rpl_ndb_sync.test:
New BitKeeper file ``mysql-test/t/rpl_ndb_sync.test''
mysql-test/t/rpl_row_basic_7ndb.test:
New BitKeeper file ``mysql-test/t/rpl_row_basic_7ndb.test''
sql/ha_ndbcluster_binlog.cc:
New BitKeeper file ``sql/ha_ndbcluster_binlog.cc''
sql/ha_ndbcluster_binlog.h:
New BitKeeper file ``sql/ha_ndbcluster_binlog.h''
sql/ha_ndbcluster_tables.h:
New BitKeeper file ``sql/ha_ndbcluster_tables.h''
sql/rpl_injector.cc:
New BitKeeper file ``sql/rpl_injector.cc''
sql/rpl_injector.h:
New BitKeeper file ``sql/rpl_injector.h''
storage/ndb/include/kernel/signaldata/DihFragCount.hpp:
New BitKeeper file ``storage/ndb/include/kernel/signaldata/DihFragCount.hpp''
according to the standard.
The idea is to use Field-classes to implement stored routines
variables. Also, we should provide facade to Item-hierarchy
by Item_field class (it is necessary, since SRVs take part
in expressions).
The patch fixes the following bugs:
- BUG#8702: Stored Procedures: No Error/Warning shown for inappropriate data
type matching;
- BUG#8768: Functions: For any unsigned data type, -ve values can be passed
and returned;
- BUG#8769: Functions: For Int datatypes, out of range values can be passed
and returned;
- BUG#9078: STORED PROCDURE: Decimal digits are not displayed when we use
DECIMAL datatype;
- BUG#9572: Stored procedures: variable type declarations ignored;
- BUG#12903: upper function does not work inside a function;
- BUG#13705: parameters to stored procedures are not verified;
- BUG#13808: ENUM type stored procedure parameter accepts non-enumerated
data;
- BUG#13909: Varchar Stored Procedure Parameter always BINARY string (ignores
CHARACTER SET);
- BUG#14161: Stored procedure cannot retrieve bigint unsigned;
- BUG#14188: BINARY variables have no 0x00 padding;
- BUG#15148: Stored procedure variables accept non-scalar values;
mysql-test/r/ctype_ujis.result:
Explicitly specify correct charset.
mysql-test/r/schema.result:
Drop our test database to not affect this test if some test
left it cause of failure.
mysql-test/r/show_check.result:
Drop our test database to not affect this test if some test
left it cause of failure.
mysql-test/r/skip_name_resolve.result:
Ignore columns with unpredictable values.
mysql-test/r/sp-big.result:
Add cleanup statement.
mysql-test/r/sp-dynamic.result:
Add cleanup statements.
mysql-test/r/sp.result:
Update result file.
mysql-test/r/sum_distinct-big.result:
Update result file.
mysql-test/r/type_newdecimal-big.result:
Update result file.
mysql-test/t/ctype_ujis.test:
Explicitly specify correct charset.
mysql-test/t/schema.test:
Drop our test database to not affect this test if some test
left it cause of failure.
mysql-test/t/show_check.test:
Drop our test database to not affect this test if some test
left it cause of failure.
mysql-test/t/skip_name_resolve.test:
Ignore columns with unpredictable values.
mysql-test/t/sp-big.test:
Add cleanup statement.
mysql-test/t/sp-dynamic.test:
Add cleanup statements.
mysql-test/t/sp.test:
Non-scalar values prohibited for assignment to SP-vars;
polishing.
mysql-test/t/type_newdecimal-big.test:
Update type specification so that the variables
can contain the large values used in the test.
sql/field.cc:
Extract create_field::init() to initialize an existing
instance of create_field from new_create_field().
sql/field.h:
Extract create_field::init() to initialize an existing
instance of create_field from new_create_field().
sql/item.cc:
- Introduce a new class: Item_sp_variable -- a base class
of stored-routine-variables classes;
- Introduce Item_case_expr -- an Item, which is used to access
to the expression of CASE statement;
sql/item.h:
- Introduce a new class: Item_sp_variable -- a base class
of stored-routine-variables classes;
- Introduce Item_case_expr -- an Item, which is used to access
to the expression of CASE statement;
sql/item_func.cc:
Pass the Field (instead of Item) for the return value of
a function to the function execution routine.
sql/item_func.h:
Pass the Field (instead of Item) for the return value of
a function to the function execution routine.
sql/mysql_priv.h:
Move create_virtual_tmp_table() out of sql_select.h.
sql/sp.cc:
Use create_result_field() instead of make_field().
sql/sp_head.cc:
- Add a function to map enum_field_types to Item::Type;
- Add sp_instr_push_case_expr instruction -- an instruction
to push CASE expression into the active running context;
- Add sp_instr_pop_case_expr instruction -- an instruction
to pop CASE expression from the active running context;
- Adapt the SP-execution code to using Fields instead of Items
for SP-vars;
- Use create_field structure for field description instead of
a set of members.
sql/sp_head.h:
- Add a function to map enum_field_types to Item::Type;
- Add sp_instr_push_case_expr instruction -- an instruction
to push CASE expression into the active running context;
- Add sp_instr_pop_case_expr instruction -- an instruction
to pop CASE expression from the active running context;
- Adapt the SP-execution code to using Fields instead of Items
for SP-vars;
- Use create_field structure for field description instead of
a set of members.
sql/sp_pcontext.cc:
- Change rules to assign an index of SP-variable: use
transparent index;
- Add an operation to retrieve a list of defined SP-vars
from the processing context recursively.
sql/sp_pcontext.h:
- Change rules to assign an index of SP-variable: use
transparent index;
- Add an operation to retrieve a list of defined SP-vars
from the processing context recursively.
sql/sp_rcontext.cc:
- Change rules to assign an index of SP-variable: use
transparent index;
- Use a tmp virtual table to store SP-vars instead of Items;
- Provide operations to work with CASE expresion.
sql/sp_rcontext.h:
- Change rules to assign an index of SP-variable: use
transparent index;
- Use a tmp virtual table to store SP-vars instead of Items;
- Provide operations to work with CASE expresion.
sql/sql_class.cc:
- Reflect Item_splocal ctor changes;
- Item_splocal::get_offset() has been renamed to get_var_idx().
sql/sql_class.h:
Polishing.
sql/sql_parse.cc:
Extract create_field::init() to initialize an existing
instance of create_field from new_create_field().
sql/sql_select.cc:
Take care of BLOB columns in create_virtual_tmp_table().
sql/sql_select.h:
Move create_virtual_tmp_table() out of sql_select.h.
sql/sql_trigger.cc:
Use boolean constants for boolean type instead of numerical ones.
sql/sql_yacc.yy:
Provide an instance of create_field for each SP-var.
mysql-test/include/sp-vars.inc:
The definitions of common-procedures, which are created
under different circumstances.
mysql-test/r/sp-vars.result:
Result file for the SP-vars test.
mysql-test/sp-vars.test:
A new test for checking SP-vars functionality.
mysqldump skips information_schema db
'use' now can use information_schema db
changed value of column 'Null' to 'NO' if column is not nullable
client/mysqldump.c:
mysqldump skips information_schema db
mysql-test/r/alter_table.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/create.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/ctype_collate.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/ctype_recoding.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/ctype_ujis.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/drop.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/func_sapdb.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/func_time.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/gis.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/information_schema.result:
Added couple of tests
mysql-test/r/information_schema_inno.result:
Removed coulmn 'CONTRAINT_METOD' from TABLE_CONSTRAINTS
Added column 'POSITION_IN_UNIQUE_CONSTRAINT' to KEY_COLUMN_USAGE
mysql-test/r/innodb.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/ndb_autodiscover.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/ps_1general.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/rpl000009.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/rpl_create_database.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/schema.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/select.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/show_check.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/sp.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/type_enum.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/r/type_ranges.result:
changed value of column 'Null' to 'NO' if column is not nullable
mysql-test/t/information_schema.test:
Added couple of tests
sql/sql_acl.cc:
Don't display 'usage' privilege in TABLE_PRIVILEGES if we have columns privileges
sql/sql_db.cc:
'use' now can use information_schema db
sql/sql_show.cc:
code cleanup
informaton_schema(IS) db now contains data about IS itself
sql/sql_yacc.yy:
A fix(wrong behavour of 'SHOW COLUMNS, SHOW KEYS' with 'where condition')
