Proposed changes:

1. Deprecation warnings in the parser:
   • on SQL_CACHE and SQL_NO_CACHE syntax,
   • on references to QC-related system variables.
2. Deprecation warnings in the command line help text of the mysqld program.

5.7

Add deprecation "no replacement" warnings to:

1. SQL_CACHE and SQL_NO_CACHE syntax in the parser,

2. any references to any QC-related system variables and help texts for their command-line counterparts:

   • have_query_cache

   • query_cache_limit

   • query_cache_min_res_unit

   • query_cache_size

   • query_cache_type

   • query_cache_wlock_invalidate

3. assignments to ndb_cache_check_time and its help text

4. {RESET, FLUSH} QUERY CACHE statements.

Note in the documentation, that QC-related variables (SHOW STATUS LIKE 'qc%') will be removed in the future release:

• Qcache_free_blocks

• Qcache_free_memory

• Qcache_hits

• Qcache_inserts

• Qcache_lowmem_prunes

• Qcache_not_cached

• Qcache_queries_in_cache

• Qcache_total_blocks

8.0

Since 8.0 still has (i.e. silently ignores) the SQL_NO_CACHE syntax and always returns false on the have_query_cache variable, maintain deprecation warnings for both like we do in 5.7 for a while.