Release date: October 8, 2019
TiDB version: 3.0.4
TiDB Ansible version: 3.0.4
performance_schema.events_statements_summary_by_digest
system table to troubleshoot performance issues at the SQL levelWHERE
clause in TiDB’s SHOW TABLE REGIONS
syntaxworker-count
and txn-batch
configuration items in Reparo to control the recovery speediosnoop
and funcslower
in TiDB Ansible to better diagnose the cluster statetxn-local-latches.enable
to false
to disable the default behavior of checking conflicts of local transactions in TiDBtidb_txn_mode
system variable of global scope in TiDB and allow using the pessimistic lock; note that TiDB still adopts the optimistic lock by defaultIndex_ids
field in TiDB slow query logs with Index_names
to improve the usability of slow query logssplit-region-max-num
parameter in the TiDB configuration file to modify the maximum number of Regions allowed in the SPLIT TABLE
syntaxOut Of Memory Quota
error instead of disconnecting the link when a SQL execution exceeds the memory limitAUTO_INCREMENT
attribute of columns in TiDB to avoid misoperations. To drop this attribute, change the tidb_allow_remove_auto_inc
system variablePRE_SPLIT_REGIONS
might cause errors in the downstream database during data replicationPREPARE
+ EXECUTE
by using the cursorContributors
Our thanks go to the following contributors from the community for helping this release:
SHOW STATS_BUCKETS
statement in hexadecimal rather than return errors when the result contains invalid Keys #12094SLEEP
function (for example, select 1 from (select sleep(1)) t;)
), column pruning causes invalid sleep(1)
during query #11953use index()
to be compatible with MySQL #12100TopN
records in the CMSketch
statistics to fix the issue that the ANALYZE
statement fails because the statement count exceeds TiDB’s limit on the size of a transaction #11914Update
statement #12483select ... limit ... offset ...
statement by pushing the Limit operator down to the IndexLookUpReader
execution logic #12378PREPARED
statement is incorrectly executed #12191UNIX_TIMESTAMP
function is used to implement partitioning #12169AUTO_INCREMENT
incorrectly allocates MAX int64
and MAX uint64
#12162WHERE
clause in the SHOW TABLE … REGIONS
and SHOW TABLE .. INDEX … REGIONS
syntaxes #12123Out Of Memory Quota
error instead of disconnecting the link when a SQL execution exceeds the memory limit #12127JSON_UNQUOTE
function handles JSON text #11955LAST INSERT ID
is incorrect when assigning values to the AUTO_INCREMENT
column in the first row (for example, insert into t (pk, c) values (1, 2), (NULL, 3)
) #12002GROUPBY
parsing rule is incorrect in the PREPARE
statement #12351sql_type
for the PREPARE
statement is not shown in the monitoring record #12331select * from t tmp where a = "aa"
) #122822019-09-11 11:17:47.999999666
should be rounded to 2019-09-11 11:17:48
.) #12258<
is equivalent to It
.) #11975[expression:1305]FUNCTION test.std_samp does not exist
) #12111Prev_stmt
field in slow query logs to output the previous statement when the last statement is COMMIT
#12180txn-local-latches.enable
to false
to disable the default behavior of checking conflicts of local transactions in TiDB #12095Index_ids
field in TiDB slow query logs with Index_names
to improve the usability of slow query logs #12061tidb_txn_mode
system variable of global scope in TiDB and allow using pessimistic lock #12049Backoff
field in the slow query logs to record the Backoff information in the commit phase of 2PC #12335PREPARE
+ EXECUTE
by using the cursor (for example, PREPARE stmt1FROM SELECT * FROM t WHERE a > ?; EXECUTE stmt1 USING @variable
) #12392tidb_enable_stmt_summary
. When this feature is enabled, TiDB counts the SQL statements and the result can be queried by using the system table performance_schema.events_statements_summary_by_digest
#12308batchRecvLoop fails
from ERROR
to INFO
) #12383tidb_allow_remove_auto_inc
variable. Dropping the AUTO INCREMENT
attribute of the column is disabled by default #12145PRE_SPLIT_REGIONS
might cause errors in the downstream database during data replication #12120split-region-max-num
variable in the configuration file so that the maximum allowable number of Regions is adjustable #12097drop index
statement fails when the index that contains an auto_increment
column referenced by two indexes #12344connection_transient_failure_count
monitoring metrics to count the number of gRPC connection errors in tikvclient
#12093-V
command is not consistent with the format of 2.X #5501pd-ctl
is invalid #1738pessimistic_txn
to true
#933node_exporter
#938iosnoop
and funcslower
in TiDB Ansible to better diagnose the cluster state #946txn_local_latches
to false