The problem happened because the the new client capability flag
CLIENT_EXTENDED_METADATA was not put into the cache entry key.
So results cached by a new client were sent to the old client (and vica versa)
with a mis-matching metadata, which made the client abort the connection on
an unexpected result set metadata packet format.
The problem was caused by the patch for:
MDEV-17832 Protocol: extensions for Pluggable types and JSON, GEOMETRY
which forgot to adjust the query cache code.
Fix:
- Adding a new member Query_cache_query_flags::client_extended_metadata,
so only clients with equal CLIENT_EXTENDED_METADATA flag values can
reuse results.
- Adding a new column CLIENT_EXTENDED_METADATA into
INFORMATION_SCHEMA.QUERY_CACHE_INFO (privided by the qc_info plugin).
The 10.5 version of the patch.
Removing DEFAULT from INFORMATION_SCHEMA columns.
DEFAULT in read-only tables is rather meaningless.
Upgrade should go smoothly.
Also fixes:
MDEV-20254 Problems with EMPTY_STRING_IS_NULL and I_S tables
Removing DEFAULT from INFORMATION_SCHEMA columns.
DEFAULT in read-only tables is rather meaningless.
Upgrade should go smoothly.
Also fixes:
MDEV-20254 Problems with EMPTY_STRING_IS_NULL and I_S tables
Hybrid functions (IF, COALESCE, etc) did not preserve the JSON property
from their arguments. The same problem was repeatable for single row subselects.
The problem happened because the method Item::is_json_type() was inconsistently
implemented across the Item hierarchy. For example, Item_hybrid_func
and Item_singlerow_subselect did not override is_json_type().
Solution:
- Removing Item::is_json_type()
- Implementing specific JSON type handlers:
Type_handler_string_json
Type_handler_varchar_json
Type_handler_tiny_blob_json
Type_handler_blob_json
Type_handler_medium_blob_json
Type_handler_long_blob_json
- Reusing the existing data type infrastructure to pass JSON
type handlers across all item types, including classes Item_hybrid_func
and Item_singlerow_subselect. Note, these two classes themselves do not
need any changes!
- Extending the data type infrastructure so data types can inherit
their properties (e.g. aggregation rules) from their base data types.
E.g. VARCHAR/JSON acts as VARCHAR, LONGTEXT/JSON acts as LONGTEXT
when mixed to a non-JSON data type. This is done by:
- adding virtual method Type_handler::type_handler_base()
- adding a helper class Type_handler_pair
- refactoring Type_handler_hybrid_field_type methods
aggregate_for_result(), aggregate_for_min_max(),
aggregate_for_num_op() to use Type_handler_pair.
This change also fixes:
MDEV-27361 Hybrid functions with JSON arguments do not send format metadata
Also, adding mtr tests for JSON replication. It was not covered yet.
And the current patch changes the replication code slightly.
UUID values
llllllll-mmmm-Vhhh-vsss-nnnnnnnnnnnn
are now stored as
nnnnnnnnnnnn-vsss-Vhhh-mmmm-llllllll
inside the record:
- the groups (segments separated by dash) are reordered right-to-left.
- the bytes inside the groups are not reordered (stored as before,
in big-endian format).
This provides a better sorting order: the earlier UUID was generated,
the higher it appears in the ORDER BY output.
Also, this change enables a good key prefix compression,
because the constant part is now in the beginning, while
the non-constant part (the timestamp) is in the end.
- Adding a new template FixedBinTypeStorage.
- Restoring classes UUID and Inet6
as primitive "storage classes" for their data types.
They derive from FixedBinTypeStorage.
These storage classes have very few server dependencies so they
can later be easily reused in smart engines, e.g. ColumnStore.
- Changing the FixedBinTypeBundle parameter from
<size_t NATIVE_LEN, size_t MAX_CHAR_LEN> to <class FbtImpl>
and fixing UUID and INET6 bundles to get their storage
classes as a parameter.
factor out the the common code for all plugin types that have a
fixed-length native binary representation and a possibly variable-length
string representation.
bzip2/lz4/lzma/lzo/snappy compression is now provided via *services*
they're almost like normal services, but in include/providers/
and they're supposed to provide exactly the same interface
as original compression libraries (but not everything,
only enough of if for the code to compile).
the services are implemented via dummy functions that return
corresponding error values (LZMA_PROG_ERROR, LZO_E_INTERNAL_ERROR, etc).
the actual compression libraries are linked into corresponding
provider plugins. Providers are daemon plugins that when loaded
replace service pointers to point to actual compression functions.
That is, run-time dependency on compression libraries is now on plugins,
and the server doesn't need any compression libraries to run, but
will automatically support the compression when a plugin is loaded.
InnoDB and Mroonga use compression plugins now. RocksDB doesn't,
because it comes with standalone utility binaries that cannot
load plugins.
Dead code cleanup:
part_info->num_parts usage was wrong and working incorrectly in
mysql_drop_partitions() because num_parts is already updated in
prep_alter_part_table(). We don't have to update part_info->partitions
because part_info is destroyed at alter_partition_lock_handling().
Cleanups:
- DBUG_EVALUATE_IF() macro replaced by shorter form DBUG_IF();
- Typo in ER_KEY_COLUMN_DOES_NOT_EXITS.
Refactorings:
- Splitted write_log_replace_delete_frm() into write_log_delete_frm()
and write_log_replace_frm();
- partition_info via DDL_LOG_STATE;
- set_part_info_exec_log_entry() removed.
DBUG_EVALUATE removed
DBUG_EVALUTATE was only added for consistency together with
DBUG_EVALUATE_IF. It is not used anywhere in the code.
DBUG_SUICIDE() fix on release build
On release DBUG_SUICIDE() was statement. It was wrong as
DBUG_SUICIDE() is used in expression context.
Also fixes MDEV-24619 Wrong result or Assertion `0' in Item::val_native / Type_handler_inet6::Item_val_native_with_conversion
Type_handler_inet6::create_item_copy() created a generic Item_copy_string,
which does not implement val_native() - it has a dummy implementation
with DBUG_ASSERT(0), which made the server crash.
Fix:
- Adding a new class Type_handler_inet6
which implements val_native().
- Fixing Type_handler_inet6::create_item_copy()
to make Item_copy_inet6 instead of Item_copy_string.
