SingleStore 7.5 was released on July 20th, 2021. Below you can find the release highlights. You can see the full feature list on our Release Notes page.
The SingleStore 7.5 release enhances Universal Storage and adds support for unlimited storage (bottomless) databases and point-in-time recovery of unlimited storage databases. Also, the release adds new built-in functions for working with JSON and unique identifiers.
Added support for multi-column hash keys (which can be
UNIQUE) on columnstore tables.
Added support for creating multi-column hash indexes on columnstore tables, using CREATE INDEX.
Added support for upserts, using
ON DUPLICATE KEY UPDATEor
IGNOREon columnstore tables with multi-column hash keys.
Added the unlimited storage feature, which allows you to store databases in a remote object store, with remote objects cached locally on the cluster to enhance performance. This is known as separation of storage and compute. Currently, the Amazon S3 remote object store and Ceph remote object store on Amazon S3 are supported.
Added support for the utf8mb4 character set, which includes encoding for emojis and additional supplementary character sets. The
collation_serverengine variables specify the server character set and collation. Although these are session variables, it is strongly recommended to set these variables globally via SQL commands or set them at server startup using SingleStore Tools.
Added "straight-to-disk" support for columnstore tables with a unique index using
INSERT … IGNORE,
INSERT … ON DUPLICATE KEY UPDATE. Straight-to-disk is when inserts and updates on columnstores bypass the rowstore (memory-backed) segment and go straight to disk.
preserve_original_colstore_jsonengine variable now defaults to
System of Record
Added point-in-time recovery (PITR), which allows you to restore a bottomless database to a specified point-in-time.
Added lock-free backup functionality, allowing backups to start without pausing concurrent online updates. Also, added the
Implementationcolumn to the
Implementationcan have either of the following values:
Usability and Programmability
Added a new function, JSON_BUILD_OBJECT, that converts a comma-separated argument list to a JSON object.
Added a new function, JSON_PRETTY, that outputs the given JSON object or JSON array in an indented and legible format.
Added two new built-in SQL commands for creating identifiers: SYS_GUID and UUID.
The data_conversion_compatibility_level engine variable can now be set to
7.5for stricter data type conversions. This new
data_conversion_compatibility_levelsetting additionally flags invalid string-to-number conversion in
Introduced a beta version of HTTP APIs that can be used to execute SQL statements over an HTTP connection.
The HTTP APIs enable you to develop custom applications and build seamless integrations with applications. The HTTP API endpoints can be easily enabled or disabled using engine variables. For more information, see HTTP API Documentation.
Added support for hash group spilling, which enables
GROUP BYqueries with result sets larger than available RAM to finish successfully.
DELETEqueries containing a join (without using
LIMIT) now only lock rows that pass the join.
Added support for executing Data Manipulation Language (DML) queries for reference tables on child aggregator nodes in addition to the master aggregator node. A new enable_dml_query_forwarding engine variable enables DML queries for reference tables to be forwarded from child aggregator nodes to the master aggregator node.
Added the SHOW REPRODUCTION command, which collects troubleshooting data for query optimizer and code generation issues for queries that fail in the compilation phase. The troubleshooting information can be displayed on the terminal or written to a file, which can then be sent to the SingleStore Technical Support team for further analysis.
Added support for reading SELECT query results in parallel, enabling faster transmission of large results sets to parallel client applications.
compile_firstsettings to the
Added the default_columnstore_table_lock_threshold engine variable. This is the threshold for the number of rows that are locked before a table lock is acquired when updating or deleting rows in a columnstore table.
Updates and deletes can now be run as a distributed transaction. This feature is enabled when the engine variable
disable_update_delete_distributed_transactionsis set to
OFF(the default). When this variable is set to
OFF, the engine variables
wait_die_retry_on_die_sleep_factorcontrol the locking behavior of the updates and deletes.
Added support for IMDSv2 in S3 pipelines.
Added support for ingesting Kafka keys using pipelines.
ADMIN-ONLY-INCLUDING-PARSE-FAILSlogging levels no longer log non-DDL operations.
Other Improvements and Fixes
Added database version information to
replay_stuck_on_low_blob_cache_spaceto the output of
SHOW DATABASE STATUS. It indicates whether the replay is stalling because of low blob cache space.
The RPC info column has been removed from the output of the
The local join optimizer now uses beam search to enable finding better query plans. The new engine variable,
optimizer_beam_width, controls the beam search width. The default value is 10. Setting this to 1 reverts to the previous behavior (prior to v7.5). Higher values (maximum is 1024) will make the query optimization time slower.
For commands that require
CREDENTIALS, you can specify them in either order (
successas a JSON key that is populated in the
DETAILSfield of the
information_schema.MV_EVENTStable for rebalance events. The value of the
successkey indicates whether a rebalance succeeded or failed.
SHOW REBALANCE STATUS,
SHOW REBALANCE ALL DATABASES STATUS,
EXPLAIN REBALANCE PARTITIONS, and
EXPLAIN REBALANCE ALL DATABASEScommands now output
Estimated_Time_Remaining_Ms, which provides a time estimate for completing a rebalance.
UNIONsupport to a wider range of cross-database queries.
Added the ability to run multiple concurrent
ALTERcommands on different tables in the same database.
multi_statement_xact_idle_timeoutengine variable, which is the time, in seconds, that is allowed for a multi-statement transaction to remain idle while holding locks.