Invalidating query cache Live text chat hookup

6854933580_2c8b688306_z

There are a couple of different techniques for creating user-specific reports. Creating a user-specific report requires the underlying data source to know the Domain Username (User ID) of the user accessing the report in order to retrieve user specific data.

Retrieving user-specific data requires the underlying data source to have a relationship between users and the data they have permission to view.

Once the underlying data source has established a relationship between the User ID and the data it has access to, it’s time to think about how to display user specific data in the report.

There are two ways of displaying user specific data: This example demonstrates using both the options to display user specific data.

invalidating query cache-3invalidating query cache-61invalidating query cache-7

Second, the query cache can be operated in 3 modes only: on, off, and on-demand.Here is a common list of some of the undocumented parameters:_allow_resetlogs_corruption _column_tracking_level _db_aging_cool_count _db_aging_freeze_cr _db_aging_hot_criteria _db_aging_stay_count _db_aging_touch_time _db_percent_hot_default _db_percent_hot_keep _db_percent_hot_recycle _init_sql_file _kghdsidx_count _log_io_size _realfree_heap_pagesize_hint _recyclebin _small_table_threshold _system_trig_enabled _trace_files_public _use_ism _use_ism_for_pga _wait_for_sync _NUMA_pool_size = 536870912 _collect_undo_stats=false _awr_restrict_mode=true _db_writer_flush_imu=false _db_cache_pre_warm=FALSE _undo_autotune = false _imu_pools = 358 _optimizer_cache_stats = false _optimizer_cost_model = io _cursor_cache_frame_bind_memory = true _db_writer_coalesce_area_size = 16777216 _kghdsidx_count = 1 _ksmg_granule_size=268435456 _two_pass=false _session_idle_bit_latches=3000Many savvy Oracle professionals commonly adjust the hidden parameters to improve the overall performance of their systems.However, because these are "undocumented" parameters, most Oracle professionals rely on publications such as "Oracle Internals" to get insights into the proper setting for the hidden parameters.OPQ is an amazing facility for improving the speed of large-table full-table scans, and some DBAs are not aware that there are a dozen hidden parameters that can be changed to affect the behavior of parallel queries.Earl Shaffer provides this query to display the parameters.I'm discounting #38551 as this happened more than once since after turning the query cache off.Unfortunately the thread finally ended so I can't checkout whether #59899 is related or not.For specialized tasks such as database tuning, it's possible to set the Oracle undocumented ("hidden" parameters).You should carefully test all undocumented parameters and get permission from Oracle technical support before using undocumented parameters in production.Suggested fix: I've switched to statement based replication now to see if that resolves the issue.show variables like 'query_%'; ------------------------------ --------- | Variable_name | Value | ------------------------------ --------- | query_alloc_block_size | 8192 | | query_cache_limit | 1048576 | | query_cache_min_res_unit | 4096 | | query_cache_size | 0 | | query_cache_type | OFF | | query_cache_wlock_invalidate | OFF | | query_prealloc_size | 8192 | ------------------------------ --------- 7 rows in set (0.01 sec) mysql show status like 'qcache%'; ------------------------- ------- | Variable_name | Value | ------------------------- ------- | Qcache_free_blocks | 0 | | Qcache_free_memory | 0 | | Qcache_hits | 0 | | Qcache_inserts | 0 | | Qcache_lowmem_prunes | 0 | | Qcache_not_cached | 0 | | Qcache_queries_in_cache | 0 | | Qcache_total_blocks | 0 | ------------------------- ------- 8 rows in set (0.03 sec) show global status like 'qcache%'; ------------------------- ------- | Variable_name | Value | ------------------------- ------- | Qcache_free_blocks | 0 | | Qcache_free_memory | 0 | | Qcache_hits | 0 | | Qcache_inserts | 0 | | Qcache_lowmem_prunes | 0 | | Qcache_not_cached | 0 | | Qcache_queries_in_cache | 0 | | Qcache_total_blocks | 0 | ------------------------- ------- 8 rows in set (0.01 sec) mysql show global variables like 'query_%'; ------------------------------ --------- | Variable_name | Value | ------------------------------ --------- | query_alloc_block_size | 8192 | | query_cache_limit | 1048576 | | query_cache_min_res_unit | 4096 | | query_cache_size | 0 | | query_cache_type | OFF | | query_cache_wlock_invalidate | OFF | | query_prealloc_size | 8192 | ------------------------------ --------- 7 rows in set (0.02 sec)Do you use ROW or MIXED mode replication?

You must have an account to comment. Please register or login here!