MySQL HeatWave Release Notes
Support was added for CAST()
of
ENUM
column values to
CHAR
or
VARCHAR
where the
ENUM
value is cast to a
FLOAT
value, as in the following
example:
SELECT CAST(CAST(enum_col
AS FLOAT) AS CHAR(3)) FROMtbl_name
;
(Bug #32618454)
Support was added for
SELECT
DISTINCT
queries that order the result set by a column
that is not defined in the SELECT
list. For
example, the following query can now be offloaded to MySQL HeatWave for
execution:
SELECT DISTINCT a FROM t1 ORDER BY c DESC;
(Bug #32583856)
Query plan statistics are now collected and stored in a statistics cache when a query is executed in MySQL HeatWave. When a new query shares query execution plan nodes with previously executed queries, the actual statistics collected from previously executed queries are used instead of estimated statistics, which improves query execution plans, cost estimations, execution times, and memory efficiency.
The statistics cache is an LRU structure. When cache capacity is
reached, the least recently used entries are evicted from the
cache as new entries are added. The maximum number of entries
permitted in the statistics cache is defined by the
rapid_stats_cache_max_entries
setting. The number of entries permitted by default is 65536,
which is enough to store statistics for 4000 to 5000 unique
queries of medium complexity.
(WL #14503)
Support was added for:
CAST() AS YEAR
. Both
variable-length and dictionary-encoded string columns values
are supported.
The FORMAT()
function.
Variable-length-encoded string columns are not supported.
(WL #14511)