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  1. Percona Server for MySQL
  2. PS-6926

Document RocksDB variables: rocksdb_table_stats_recalc_threshold_pct, rocksdb_table_stats_recalc_threshold_count, rocksdb_table_stats_background_thread_nice_value, rocksdb_table_stats_max_num_rows_scanned, rocksdb_table_stats_use_table_scan.

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    Details

    • Type: New Feature
    • Status: Done
    • Priority: Medium
    • Resolution: Fixed
    • Affects Version/s: 8.0.19-10, 5.7.x, Not 5.6.x
    • Fix Version/s: 8.0.20-11
    • Component/s: Documentation, MyRocks
    • Labels:
      None
    • Needs Review:
      Yes

      Description

      Implemented at https://github.com/percona/percona-server/pull/3716/files

      1. Add a new variable "rocksdb_table_stats_recalc_threshold_pct":

         :dyn: Yes
         :scope: Global
         :vartype: UINT
         :default: 10
          :min = 0
          :max =  100 (RDB_TBL_STATS_RECALC_THRESHOLD_PCT_MAX)
      
                               "Percentage of number of modified rows over total "
                               "number of rows to trigger stats recalculation",
      

      2. Add a new variable "rocksdb_table_stats_recalc_threshold_count":

         :dyn: Yes
         :scope: Global
         :vartype: ULONGLONG
         :default: 100
          :min = 0
          :max =  UINT64_MAX
      
          "Number of modified rows to trigger stats recalculation"
      

      3. Add a new variable "rocksdb_table_stats_background_thread_nice_value":

         :dyn: Yes
         :scope: Global
         :vartype: INT
         :default: 19
          :min = -20 (THREAD_PRIO_MIN)
          :max =  19 (THREAD_PRIO_MAX)
      
         "nice value for index stats",
      

      4. Add a new variable "rocksdb_table_stats_max_num_rows_scanned":

         :dyn: Yes
         :scope: Global
         :vartype: ULONGLONG
         :default: 0
          :min = 0
          :max =  UINT64_MAX
      
          "The maximum number of rows to scan in table scan based "
          "cardinality calculation",
      

      5. Add a new variable "rocksdb_table_stats_use_table_scan":

         :dyn: Yes
         :scope: Global
         :vartype: BOOL
         :default: FALSE
      
         "Enable table scan based index calculation."
      

      6. Add a new variable "rocksdb_trace_block_cache_access":

         :dyn: Yes
         :scope: Global
         :vartype: String
         :default: "" (empty string)
      
          "Block cache trace option string. The format is "
          "sampling_frequency:max_trace_file_size:trace_file_name. "
          "sampling_frequency and max_trace_file_size are positive integers. The "
          "block accesses are saved to the "
          "rocksdb_datadir/block_cache_traces/trace_file_name.",
      

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                Assignee:
                patrick.birch Patrick Birch
                Reporter:
                przemyslaw.skibinski Przemyslaw Skibinski
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                  Resolved:

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