Releases: pingcap/tidb
Releases · pingcap/tidb
tidb-server v2.1.8
- Fix the issue that the processing logic of
GROUP_CONCAT
function is incompatible with MySQL when there is a NULL-valued parameter #9930 - Fix the equality check issue of decimal values in the
Distinct
mode #9931 - Fix the collation compatibility issue of the date, datetime, and timestamp types for the
SHOW FULL COLUMNS
statement - Fix the issue that the row count estimation is inaccurate when the filtering condition contains correlated columns #9937
- Fix the compatibility issue between the
DATE_ADD
andDATE_SUB
functions - Support the
%H
format for theSTR_TO_DATE
function to improve compatibility #9964 - Fix the issue that the result is wrong when the
GROUP_CONCAT
function groups by a unique index #9969 - Return a warning when the Optimizer Hints contains an unmatched table name #9970
- Unify the log format to facilitate collecting logs using tools for analysis Unified Log Format
- Fix the issue that a lot of NULL values cause inaccurate statistics estimation #9979
- Fix the issue that an error is reported when the default value of the TIMESTAMP type is the boundary value #9987
- Validate the value of
time_zone
#10000 - Support the
2019.01.01
time format #10001 - Fix the issue that the row count estimation is displayed incorrectly in the result returned by the
EXPLAIN
statement in some cases #10044 - Fix the issue that
KILL TIDB [session id]
cannot instantly stop the execution of a statement in some cases #9976 - Fix the predicate pushdown issue of constant filtering conditions in some cases #10049
- Fix the issue that a read-only statement is not processed correctly in some cases #10048
tidb-server v2.1.7
- Fix the issue of longer startup time when upgrading the program caused by canceling DDL operations #9768
- Fix the issue that the
check-mb4-value-in-utf8
configuration item is in the wrong position in theconfig.example.toml
file #9852 - Improve the compatibility of the
str_to_date
built-in function with MySQL #9817 - Fix the compatibility issue of the
last_day
built-in function #9750 - Add the
tidb_table_id
column forinfoschema.tables
to facilitate gettingtable_id
by using SQL statements and add thetidb_indexes
system table to manage the relationship between Table and Index #9862 - Add a check about the null definition of Table Partition #9663
- Change the privileges required by
Truncate Table
fromDelete
toDrop
to make it consistent with MySQL #9876 - Support using subqueries in the
DO
statement #9877 - Fix the issue that the
default_week_format
variable does not take effect in theweek
function #9753 - Support the plugin framework #9880, #9888
- Support checking the enabling state of binlog by using the
log_bin
system variable #9634 - Support checking the Pump/Drainer status by using SQL statements #9896
- Fix the compatibility issue about checking mb4 character on utf8 when upgrading TiDB #9887
- Fix the panic issue when the aggregate function calculates JSON data in some cases #9927
tidb-server v3.0.0-beta.1
SQL Optimizer
- Support calculating the Cartesian product by using
Sort Merge Join
#9032 - Support Skyline Pruning, with some rules to prevent the execution plan from relying too heavily on statistics #9337
- Support Window Functions
- Add a type of statistic that indicates the order correlation between columns and the handle column #9315
SQL Execution Engine
- Add built-in functions:
- Optimize the Chunk size based on the query context, to reduce the execution time of SQL statements and resources consumption of the cluster #6489
Privilege management
Server
- Add the
/debug/zip
HTTP interface to get information of the current TiDB instance #9651 - Support the
show pump status
andshow drainer status
SQL statements to check the Pump or Drainer status 9456 - Support modifying the Pump or Drainer status by using SQL statements #9789
- Support adding HASH fingerprints to SQL text for easy tracking of slow SQL statements #9662
- Add the
log_bin
system variable (“0” by default) to control the enabling state of binlog; only support checking the state currently #9343 - Support managing the sending binlog strategy by using the configuration file #9864
- Support querying the slow log by using the
INFORMATION_SCHEMA.SLOW_QUERY
memory table #9290 - Change the MySQL version displayed in TiDB from 5.7.10 to 5.7.25 #9553
- Unify the log format for easy collection and analysis by tools
- Add the
high_error_rate_feedback_total
monitoring item to record the difference between the actual data volume and the estimated data volume based on statistics #9209 - Add the QPS monitoring item in the database dimension, which can be enabled by using a configuration item #9151
DDL
- Add the
ddl_error_count_limit
global variable (“512” by default) to limit the number of DDL task retries (If this number exceeds the limit, the DDL task is canceled) #9295 - Support ALTER ALGORITHM
INPLACE
/INSTANT
#8811 - Support the
SHOW CREATE VIEW
statement #9309 - Support the
SHOW CREATE USER
statement #9240
tidb-server v2.1.6
SQL Optimizer/Executor
- Optimize planner to select the outer table based on cost when both tables are specified in Hint of
TIDB_INLJ
#9615 - Fix the issue that
IndexScan
cannot be selected correctly in some cases
#9587 - Fix incompatibility with MySQL of check in the
agg
function in subqueries #9551 - Make
show stats_histograms
only output valid columns to avoid panics
#9502
Server
- Support the
log_bin
variable to enable/disable Binlog #9634 - Add a sanity check for transactions to avoid false transaction commit #9559
- Fix the issue that setting variables may lead to panic #9539
- change MySQL version from 5.7.10 to 5.7.25 #9556
DDL
tidb-server v2.1.5
SQL Optimizer/Executor
- Make
SHOW CREATE TABLE
do not print the column charset information when the charset information of a column is the same with that of a table, to improve the compatibility ofSHOW CREATE TABLE
with MySQL #9306 - Fix the panic or the wrong result of the
Sort
operator in some cases by extractingScalarFunc
fromSort
to aProjection
operator for computing to simplify the computing logic ofSort
#9319 - Remove the sorting field with constant values in the
Sort
operator #9335, #9440 - Fix the data overflow issue when inserting data into an unsigned integer column #9339
- Set
cast_as_binary
toNULL
when the length of the target binary exceedsmax_allowed_packet
#9349 - Optimize the constant folding process of
IF
andIFNULL
#9351 - Optimize the index selection of TiDB using skyline pruning to improve the stability of simple queries #9356
- Support computing the selectivity of the
DNF
expression #9405 - Fix the wrong SQL query result of
!=ANY()
and=ALL()
in some cases #9403 - Fix the panic or the wrong result when the Join Key types of two tables on which the
Merge Join
operation is performed are different #9438 - Fix the issue that the result of the
RAND()
function is not compatible with MySQL #9446 - Refactor the logic of
Semi Join
processingNULL
and the empty result set to get the correct result and improve the compatibility with MySQL #9449
Server
- Add the
tidb_constraint_check_in_place
system variable to check the data uniqueness constraint when executing theINSERT
statement #9401 - Fix the issue that the value of the
tidb_force_priority
system variable is different from that set in the configuration file #9347 - Add the
current_db
field in general logs to print the name of the currently used database #9346 - Add an HTTP API of obtaining the table information with the table ID #9408
- Fix the issue that
LOAD DATA
loads incorrect data in some cases #9414 - Fix the issue that it takes a long time to build a connection between the MySQL client and TiDB in some cases #9451
DDL
- Fix some issues when canceling the
DROP COLUMN
operation #9352 - Fix some issues when canceling the
DROP
orADD
partitioned table operation #9376 - Fix the issue that
ADMIN CHECK TABLE
mistakenly reports the data index inconsistency in some cases #9399 - Fix the time zone issue of the
TIMESTAMP
default value #9108
tidb-server v2.1.4
SQL Optimizer/Executor
- Fix the issue that the
VALUES
function does not handle the FLOAT type correctly #9223 - Fix the wrong result issue when casting Float to String in some cases #9227
- Fix the wrong result issue of the
FORMAT
function in some cases #9235 - Fix the panic issue when handling the Join query in some cases #9264
- Fix the issue that the
VALUES
function does not handle the ENUM type correctly #9280 - Fix the wrong result issue of
DATE_ADD
/DATE_SUB
in some cases #9284
Server
- Optimize the "reload privilege success" log and change it to the DEBUG level #9274
DDL
tidb-server v2.1.3
SQL Optimizer/Executor
- Fix the panic issue of Prepared Plan Cache in some cases #8826
- Fix the issue that Range computing is wrong when the index is a prefix index #8851
- Make
CAST(str AS TIME(N))
return null if the string is in the illegalTIME
format whenSQL_MODE
is not strict #8966 - Fix the panic issue of Generated Column during the process of
UPDATE
in some cases #8980 - Fix the upper bound overflow issue of the statistics histogram in some cases #8989
- Support Range for
_tidb_rowid
construction queries, to avoid full table scan and reduce cluster stress #9059 - Return an error when the
CAST(AS TIME)
precision is too big #9058 - Allow using
Sort Merge Join
in the Cartesian product #9037 - Fix the issue that the statistics worker cannot resume after the panic in some cases #9085
- Fix the issue that
Sort Merge Join
returns the wrong result in some cases #9046 - Support returning the JSON type in the
CASE
clause #8355
Server
- Return a warning instead of an error when the non-TiDB hint exists in the comment #8766
- Verify the validity of the configured TIMEZONE value #8879
- Optimize the
QueryDurationHistogram
metrics item to display more statement types #8875 - Fix the lower bound overflow issue of bigint in some cases #8544
- Support the
ALLOW_INVALID_DATES
SQL mode #9110
DDL
- Fix a
RENAME TABLE
compatibility issue to keep the behavior consistent with that of MySQL #8808 - Support making concurrent changes of
ADD INDEX
take effect immediately #8786 - Fix the
UPDATE
panic issue during the process ofADD COLUMN
in some cases #8906 - Fix the issue of concurrently creating Table Partition in some cases #8902
- Support converting the
utf8
character set toutf8mb4
#8951 #9152 - Fix the issue of Shard Bits overflow #8976
- Support outputting the column character sets in
SHOW CREATE TABLE
#9053 - Fix the issue of the maximum length limit of the varchar type column in
utf8mb4
#8818 - Support
ALTER TABLE TRUNCATE TABLE PARTITION
#9093 - Resolve the charset when the charset is not provided #9147
tidb-server v3.0.0-beta
New Features
- Support View
- Support Window Function
- Support Range Partition
- Support Hash Partition
SQL Optimizer
- Re-support the optimization rule of
AggregationElimination
#7676 - Optimize the
NOT EXISTS
subquery and convert it to Anti Semi Join #7842 - Add the
tidb_enable_cascades_planner
variable to support the new Cascades optimizer. Currently, the Cascades optimizer is not yet fully implemented and is turned off by default #7879 - Support using Index Join in transactions #7877
- Optimize the constant propagation on the Outer Join, so that the filtering conditions related to the Outer table in the Join result can be pushed down through the Outer Join to the Outer table, reducing the useless calculation of the Outer Join and improving the execution performance #7794
- Adjust the optimization rule of Projection Elimination to the position after the Aggregation Elimination, to avoid redundant
Project
operators #7909 - Optimize the
IFNULL
function and eliminate this function when the input parameter has a non-NULL attribute #7924 - Support building range for
_tidb_rowid
, to avoid full table scan and reduce cluster stress #8047 - Optimize the
IN
subquery to do the Inner Join after the aggregation, and add thetidb_opt_insubq_to_join_and_agg
variable to control whether to enable this optimization rule and open it by default #7531 - Support using subqueries in the
DO
statement #8343 - Add the optimization rule of Outer Join elimination to reduce unnecessary table scan and Join operations and improve execution performance #8021
- Modify the Hint behavior of the
TIDB_INLJ
optimizer, and the optimizer will use the table specified in Hint as the Inner table of Index Join #8243 - Use
PointGet
in a wide range so that it can be used when the execution plan cache of thePrepare
statement takes effect #8108 - Introduce the greedy
Join Reorder
algorithm to optimize the join order selection when joining multiple tables #8394 - Support View #8757
- Support Window Function #8630
- Return warning to the client when
TIDB_INLJ
is not in effect, to enhance usability #9037 - Support deducing the statistics for filtered data based on filtering conditions and table statistics #7921
- Improve the Partition Pruning optimization rule of Range Partition #8885
SQL Executor
- Optimize the
Merge Join
operator to support the emptyON
condition #9037 - Optimize the log and print the user variables used when executing the
EXECUTE
statement #7684 - Optimize the log to print slow query information for the
COMMIT
statement #7951 - Support the
EXPLAIN ANALYZE
feature to make the SQL tuning process easier #7827 - Optimize the write performance of wide tables with many columns #7935
- Support
admin show next_row_id
#8242 - Add the
tidb_init_chunk_size
variable to control the size of the initial Chunk used by the execution engine #8480 - Improve
shard_row_id_bits
and cross-check the auto-increment ID #8936
Prepare
Statement
- Prohibit adding the
Prepare
statement containing subqueries to the query plan cache to guarantee the query plan is correct when different user variables are input #8064 - Optimize the query plan cache to guarantee the plan can be cached when the statement contains non-deterministic functions #8105
- Optimize the query plan cache to guarantee the query plan of
DELETE
/UPDATE
/INSERT
can be cached #8107 - Optimize the query plan cache to remove the corresponding plan when executing the
DEALLOCATE
statement #8332 - Optimize the query plan cache to avoid the TiDB OOM issue caused by caching too many plans by limiting the memory usage #8339
- Optimize the
Prepare
statement to support using the?
placeholder in theORDER BY
/GROUP BY
/LIMIT
clause #8206
Privilege Management
- Add the privilege check for the
ANALYZE
statement #8486 - Add the privilege check for the
USE
statement #8414 - Add the privilege check for the
SET GLOBAL
statement #8837 - Add the privilege check for the
SHOW PROCESSLIST
statement #7858
Server
- Support the
Trace
feature #9029 - Support the plugin framework #8788
- Support using
unix_socket
and TCP simultaneously to connect to the database #8836 - Support the
interactive_timeout
system variable #8573 - Support the
wait_timeout
system variable #8346 - Support splitting a transaction into multiple transactions based on the number of statements using the
tidb_batch_commit
variable #8293 - Support using the
ADMIN SHOW SLOW
statement to check slow logs #7785
Compatibility
- Support the
ALLOW_INVALID_DATES
SQL mode #9027 - Improve
LoadData
fault-tolerance for the CSV file #9005 - Support the MySQL 320 handshake protocol #8812
- Support using the unsigned bigint column as the auto-increment column #8181
- Support the
SHOW CREATE DATABASE IF NOT EXISTS
syntax #8926 - Abandon the predicate pushdown operation when the filtering condition contains a user variable to improve the compatibility with MySQL’s behavior of using user variables to mock the Window Function behavior #8412
DDL
- Support fast recovery of mistakenly deleted tables #7937
- Support adjusting the number of concurrencies of
ADD INDEX
dynamically #8295 - Support changing the character set of tables or columns to
utf8
/utf8mb4
#8037 - Change the default character set from
utf8
toutf8mb4
#7965 - Support Range Partition #8011
tidb-server v2.0.11
- Fix the issue that the error is not handled properly when PD is in an abnormal condition #8764 #8923
- Fix the issue that the
Rename
operation on a table in TiDB is not compatible with that in MySQL #8809 - Fix the issue that the error message is wrongly reported when the
ADMIN CHECK TABLE
operation is performed in the process of executing theADD INDEX
statement #8750 - Fix the issue that the prefix index range is incorrect in some cases #8877
- Fix the panic issue of the
UPDATE
statement when columns are added in some cases #8904
tidb-server v2.1.2
- Make TiDB compatible with TiDB-Binlog of the Kafka version #8747
- Improve the exit mechanism of TiDB in a rolling update #8707
- Fix the panic issue caused by adding the index for the generated column in some cases #8676
- Fix the issue that the optimizer cannot find the optimal query plan when
TIDB_SMJ Hint
exists in the SQL statement in some cases #8729 - Fix the issue that
AntiSemiJoin
returns an incorrect result in some cases #8730 - Improve the valid character check of the
utf8
character set #8754 - Fix the issue that the field of the time type might return an incorrect result when the write operation is performed before the read operation in a transaction #8746