8 Release Notes
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To deploy a SingleStoreDB 7.
8 cluster, refer to the Deploy SingleStoreDB Guide.
To upgrade a self-managed install to this release, follow this guide.
To make a backup of a database in this release or to restore a database backup to this release, follow this guide.
NEW RESERVED PREFIX for tables:
Starting with the 7.
8 release, there is a new reserved prefix for column names:
_This is reserved for internal use only.
$!$ Before you upgrade to SingleStoreDB 7. 8, SingleStore recommends that "_ $!$" is not used as a prefix of column names in your existing tables. If there are existing column names starting with this prefix, you should consider renaming them to avoid potential issues in the future.
This is not mandatory.
DDL commands will not allow the creation of new tables with that prefix, but DML commands will still allow users to access existing objects with that prefix.
For a list of all new features and bug fixes, see the maintenance release changelog.
New Feature: SingleStore now supports Flexible Parallelism, which allows multiple cores on the same node to access the same database partition.
With Flexible Parallelism, as database partitions are created they are divided into sub-partitions.
As a query runs on a leaf node, multiple cores working on behalf of the query can process different sub-partitions of a partition in parallel. As an example, if you are currently at one partition per core with Flexible Parallelism, doubling the size of your cluster and then rebalancing will result in two cores for each partition. As a result, a simple query that scans and aggregates all the data in a single partition will now execute more quickly than it did before.
Added new engine variables used for enabling and configuring Flexible Parallelism:
to_ physical_ partition_ ratio
parallelism_ per_ leaf_ core
leaf_ core_ count The existing engine variable
degree_ of_ parallelism
For more information, see Flexible Parallelism.
New Function: Added the
ISNUMERICfunction, used to determine whether the provided expression is a valid numeric type.
New Function: Added the
SESSION_function, used to return the user name you specified when connecting to the server, and the client host from which you connected.
New Function: Added the
SETfunction, used to initialize a user-defined session variable.
New Function: Added new vector functions, namely
Enhancement: Added support for
TRIMis now multi-byte safe which means the result of an operation using
TRIMis either a valid string or an unmodified string.
Enhancement: Unlimited storage databases now support the
BACKUP … WITH SPLIT PARTITIONScommand.
New Command: The
DROP MILESTONEcommand is used to delete a milestone of a currently attached database.
Improved performance for columnstore seeks into string columns – now it is no longer necessary to scan an entire segment to look up the data for a string value for a row when seeking to find that one row.
A new clause "AS new_
db_ name" has been added to the
RESTORE DATABASEcommand which allows the use of the full original backup path if trying to restore to a new database name.
SECRET- Added the ability to hide credentials from queries.
Passing credentials in queries can leave them exposed in plain text during parameterization and they can be seen in logs and the process list. To counter this, you can use the
SECRETfunction (similar in function to
SECRETtakes a string (such as a password or other sensitive information) and replaces it with the literal string "<password>" during parameterization.
The string is unchanged for the query however.CALL db.do_something_useful('root', SECRET('super-secret-password'));
See SECRET for more information.
Enhancement: Added per privilege transferability from one user to another via the new
SYSTEM_grant in the
REVOKEsecurity management command.
A new engine variable,
privilege_, must be set to
per_for this functionality to work as expected.
privilege Also, this new functionality will affect the results of the
privilege_engine variable remains on the default value of
grant_, then the output is one row and can include the
WITH GRANT OPTIONprivilege.
If the value of
per_, then the output can be two rows.
privilege The first row will display the non-transferable privileges. The second row will display the transferable privileges.
Enhancement: Added new
PROFILEreproduction clause syntax.
EXPLAIN REPROoutputs the explain information in JSON format and provides important debugging information.
EXPLAIN REPROwill work for
PROFILE REPROsyntax will replace the need to set the engine variable
profile_ for_ debug
The engine variable will continue to be supported for backward compatibility.
Enhancement: Added ability to match a computed column expression and the same expression appearing in a query, to improve query performance, especially for indexed computed JSON fields.
The enhancement promotes data independence between the physical and application layer.
GROUP BYstatements is enabled by default starting in 7.
8. Added an additional engine variable,
minimal_ disk_ space If a node has less disk space than
spilling_(default is 500MB), queries on that node that require spilling will fail instead of spilling to disk.
minimal_ disk_ space
Materialized CTEs are now on by default and no longer considered a preview feature.
Reduced the memory usage of
approx_by using a more compact representation.
Existing queries are no longer recompiled on minor upgrades (from 7.
8. x to 7. 8. y for example).
CREATE_to the information_
USER schema. TABLES table, to show the time of the latest update the table, the user who made the change, and the user who created the table. For existing tables, the
ALTER_value will be NULL until the table is altered.
TIME For new tables,
ALTER_will be the same as
FLAGScolumn to the
information_table, to indicate whether a view is a Table Valued Function (TVF).
schema. VIEWS A value of
IS_indicates a TVF.
TABLE_ VALUED_ FUNCTION
An internal component, the LLVM code generation framework, was updated to version 10 from version 3.
8. This improves performance of query compilation for DELETES on tables with a very large number of columns.
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Last modified: March 14, 2023