The intent of this patch is to avoid copying arguments from
a pair "Item **args, uint arg_count" to List<Item> in
sp_head::execute_function(). If the number of a stored function parameters
is huge, such copying can affect performance.
Change:
1. Adding a new method Row_definition_list::adjust_formal_params_to_actual_params,
which accepts a pair of "Item **, uint".
2. Modifying the code to use the new method:
- the calls for sp_rcontext::retrieve_field_definitions() and
Row_definition_list::adjust_formal_params_to_actual_params() have
been moved from sp_rcontext::create() to sp_head::rcontext_create(),
to handle different argument notations easier (Item** vs List<Item>).
- sp_rcontext::create() now assumes that the passed Row_definition_list
is already adjusted to the actual SP parameters, and all "TYPE OF"
and "ROWTYPE OF" references are resolved.
3. Removing creation of List<Item> in sp_head::execute_procedure(),
using the code with "Item**, uint" notation instead.
4. Improvement of the code for MDEV-10577:
As a good side effect, this patch gets rid of double security context
switch inside sp_head::execute_trigger():
sp_rcontext is created when the context is already switched,
so the second context switch inside sp_head::rcontext_create() was
redundant. This is solved by adding a "bool switch_secutiry_ctx" parameter
to rcontext_create(), so now execute_function() and execute_procedure()
pass "true", while execute_trigger() passes "false".
Moving a few methods from sp_rcontext to different classes:
- Table_ident::resolve_table_rowtype_ref
- Qualified_column_ident::resolve_type_ref
- Row_definition_list::resolve_table_rowtype_ref
- Row_definition_list::adjust_formal_params_to_actual_params
It easier to reuse these methods this way in the future.
Implement Field_timestamp::save_in_field(timestamp_field)
that stores timestamp values without converting them to MYSQL_TIME
and back, because this conversion is lossy around DST change time.
This fixes main.old-mode test.
This is 10.2 version of f8a800bec81
Implement a special Copy_func function for timestamps, that copies
timestamps without converting them to MYSQL_TIME (the conversion is
lossy around DST change time).
This fixes ALTER TABLE part of main.old-mode test.
This is 10.2 version of f4f48e06215
make insert NULL into a timestamp mark the field as having an
explicit value. So that the field won't be assigned the value
again in TABLE::update_default_field()
make Item_func_now_local::save_in_field(timestamp_field) not to go
through MYSQL_TIME - this conversion is lossy around DST change times.
This fixes inserting a default value into a timestamp field.
Storage engine independent support for column compression.
TINYBLOB, BLOB, MEDIUMBLOB, LONGBLOB, TINYTEXT, TEXT, MEDIUMTEXT, LONGTEXT,
VARCHAR and VARBINARY columns can be compressed.
New COMPRESSED column attribute added:
COMPRESSED[=<compression_method>]
System variables added:
column_compression_threshold
column_compression_zlib_level
column_compression_zlib_strategy
column_compression_zlib_wrap
Status variables added:
Column_compressions
Column_decompressions
Limitations:
- the only supported method currently is zlib
- CSV storage engine stores data uncompressed on-disk even if COMPRESSED
attribute is present
- it is not possible to create indexes over compressed columns.
- Adding new virtual methods in Type_handler:
* Column_definition_prepare_stage1()
* Column_definition_prepare_stage2()
* calc_pack_length()
- Using new methods to remove type specific code in:
* Global function calc_pack_length()
* Column_definition::prepare_create_field()
* The loop body mysql_prepare_create_table()
* Column_definition::sp_prepare_create_field()
* one `AS OF NOW`, multiple `VERSIONING` partitions;
* rotation of `VERSIONING` partitions by record count, time period;
* rotation is multi-threaded;
* conventional subpartitions as bottom level for versioned partitions;
* `DEFAULT` keyword selects first `VERSIONING` partition;
* ALTER TABLE ADD/DROP partition;
* REBUILD PARTITION basic operation.
* sys fields are NULL by default (with exceptions, see comment about NOT_NULL_FLAG in #77);
* error codes renamed, messages cleared out;
* SHOW CREATE TABLE fixed;
* set_max() fix;
* redundant flag setters/getters removed;
* flags are set in sql_yacc.yy, redundant copy_info_about_generated_fields() eliminated.
