if a bunch of tables are prelocked, when a table is actually
needed in the routine, open_tables picks one table out of the
prelocked list with a smallest "distance". Distance is simply
a difference between the actual table lock and the requested
table lock. Say, if the prelocked set contains both t1 write-locked
and t1 read-locked, than an UPDATE will prefer write-locked t1
and SELECT will prefer read-locked. if there's only write-locked
table in the set, both UPDATE and SELECT will use it.
this doesn't distingush between UPDATE and INSERT, but INSERT
marks tables with tables->for_insert_data=1, which causes
prelocking to invoke add_internal_tables() and prepare sequences
for execution.
in this bug there were two prelocked t1's, one for INSERT (with
for_insert_data=1) and one for UPDATE.
INSERT picks the second (they both are write-locked, so the distance is
the same), its sequence is not prepared and crashes.
Let's add for_insert_data as the lowest bit into the distance.
The issue was that unpack_vcol_info_from_frm() wrongly linked the used
sequence tables into tables->internal_tables when more than one sequence
table was used.
Other things:
- Fixed internal_table_exists() to take db into account.
(This is making the code easier to read. As we where comparing
pointers the old code also worked).
Only do trigger prelocking for tables that are doing to be
modified (with a write lock). A table can cause prelocking
if its DEFAULT value is used (because DEFAULT can be NEXTVAL),
even if the table itself is only used for reads. Don't process
triggers for such a table
Lots of different cases, SELECT, SELECT DEFAULT(),
UPDATE t SET x=DEFAULT, prepares statements,
opening of a table for the I_S, prelocking (so TL_WRITE),
insert with subquery (so SQLCOM_SELECT), etc.
Don't check NEXTVAL privileges in fix_fields() anymore, it cannot
possibly handle all the cases correctly. Make a special method
Item_func_nextval::check_access() for that and invoke it from
* fix_fields on explicit SELECT NEXTVAL()
(but not if NEXTVAL() is used in a DEFAULT clause)
* when DEFAULT bareword in used in, say, UPDATE t SET x=DEFAULT
(but not if DEFAULT() itself is used in a DEFAULT clause)
* in CREATE TABLE
* in ALTER TABLE ALGORITHM=INPLACE (that doesn't go CREATE TABLE path)
* on INSERT
helpers
* Virtual_column_info::check_access() to walk the item tree and invoke
Item::check_access()
* TABLE::check_sequence_privileges() to iterate default expressions
and invoke Virtual_column_info::check_access()
also, single-table UPDATE in prepared statements now associates
value items with fields just as multi-update already did, fixes the
case of PREPARE s "UPDATE t SET x=?"; EXECUTE s USING DEFAULT.
Two new error codes ER_SEQUENCE_TABLE_HAS_TOO_FEW_ROWS and
ER_SEQUENCE_TABLE_HAS_TOO_MANY_ROWS were introduced in MDEV-36032 in
both 10.11 and, as part of MDEV-22491, 12.0. Here we remove them from
10.11, but they should remain in 12.0.
insufficient grants
Defer privilege checking until fix_fields. This way ALTER will behave
consistently with CREATE, and require the same privileges to sequence
column (SELECT/INSERT)
To check the rows, the table needs to be opened. To that end, and like
MDEV-36038, we force COPY algorithm on ALTER TABLE ... SEQUENCE=1.
This also results in checking the sequence state / metadata.
The table structure was already validated before this patch.
Get rid of need of matherialization for usual INSERT (cache results in
Item_cache* if needed)
- subqueries in VALUE do not see new records in the table we are
inserting to
- subqueries in RETIRNING prohibited to use the table we are inserting to
check sequence privileges in Item_func_nextval::fix_fields(),
just like column privileges are checked in Item_field::fix_fields()
remove sequence specific hacks that kinda made sequence privilege
checks works, but not in all cases. And they were too lax,
didn't requre SELECT privilege for NEXTVAL. Also INSERT privilege looks
wrong here, UPDATE would've been more appropriate, but won't
change that for compatibility reasons.
also fixes
MDEV-36413 User without any privileges to a sequence can read from it and modify it via column default
mysql_alter_table(): Consider ha_sequence::storage_ht() when determining
if the storage engine changed.
ha_sequence::check_if_supported_inplace_alter(): A new function, to
ensure that ha_innobase::check_if_supported_inplace_alter() will be
called on ALTER TABLE name_of_sequence SEQUENCE=0.
ha_innobase::check_if_supported_inplace_alter(): For any change of
the SEQUENCE attribute, always return HA_ALTER_INPLACE_NOT_SUPPORTED,
forcing ALGORITHM=COPY.
Item:print_for_table_def() uses QT_TO_SYSTEM_CHARSET to print
the DEFAULT expression into FRM file during CREATE TABLE.
Therefore, the expression is encoded in utf8 in FRM.
get_field_default_value() erroneously used field->charset() to
print the DEFAULT expression at SHOW CREATE TABLE time.
Fixing get_field_default_value() to use &my_charset_utf8mb4_general_ci instead.
This makes DEFAULT work in the way way with:
- virtual column expressions:
if (field->vcol_info)
{
StringBuffer<MAX_FIELD_WIDTH> str(&my_charset_utf8mb4_general_ci);
field->vcol_info->print(&str);
- check constraint expressions:
if (field->check_constraint)
{
StringBuffer<MAX_FIELD_WIDTH> str(&my_charset_utf8mb4_general_ci);
field->check_constraint->print(&str);
Additional cleanup:
Fixing system_charset_info to &my_charset_utf8mb4_general_ci in a few
places to make non-BMP characters work in DEFAULT, virtual column,
check constraint expressions.
When adding a column or index that uses plugin-defined
sysvar-based options with CREATE ... LIKE the server
was using the current value of the sysvar, not the default one.
Because parse_option_list() function was used both in create
and open and it tried to guess when it's create (need to use
current sysvar value and add a new name=value pair to the list)
or open (need to use default, without extending the list).
Let's move the list extending functionality into a separate
function and call it explicitly when needed. Operations that
add new objects (CREATE, ALTER ... ADD) will extend the list,
other operations (ALTER, CREATE ... LIKE, open) will not.
safety first - tell mariadb client not to execute dangerous
cli commands, they cannot be present in the dump anyway.
wrapping the command in /*!999999 ..... */ guarantees that
if a non-mariadb-cli client loads the dump and sends it to the
server - the server will ignore the command it doesn't understand
The bitmap is temporarily flipped to ~0 for the sake of checking all
fields. It needs to be restored because it will be reused in second
and subsequent ps execution.
Like all IF NOT EXISTS syntax, a Note should be generated.
The original commit of Seqeuences cleared the IF NOT EXISTS part
in the sql/sql_yacc.yy with lex->create_info.init(). Without this
bit set there was no way it could do anything other than error.
To remedy this removal, the sql_yacc.yy components have been
minimised as they where all set at the beginning of the ALTER.
This way the opt_if_not_exists correctly set the IF_EXISTS flag.
In MDEV-13005 (bb4dd70e7c) the error code changed, requiring
ER_UNKNOWN_SEQUENCES to be handled in the function
No_such_table_error_handler::handle_condition.
