Delete events #10969 @3AceShowHand Starting from v8.4.0, TiDB and TiCDC introduce the Checksum V2 algorithm to address issues of Checksum V1 in verifying old values in Update or Delete events after ADD COLUMN spill system vari- able to control whether TiDB supports disk spill for the concurrent HashAgg algorithm. In future versions, the tidb_enable_parallel_hashagg_spill system variable will be deprecated. Y Y Y Y Y Y Y Y Y Y Y Y Cast functions and operators Y Y Y Y Y Y Y Y Y Y Y Y Encryption and compression functions Y Y Y Y Y Y Y Y Y Y Y Y Vector functions and operators E N N N N N N N N N N N Information

Delete events #10969 @3AceShowHand Starting from v8.4.0, TiDB and TiCDC introduce the Checksum V2 algorithm to address issues of Checksum V1 in verifying old values in Update or Delete events after ADD COLUMN spill system vari- able to control whether TiDB supports disk spill for the concurrent HashAgg algorithm. In future versions, the tidb_enable_parallel_hashagg_spill system variable will be deprecated. Y Y Y Y Y Y Y Y Y Y Y Y Cast functions and operators Y Y Y Y Y Y Y Y Y Y Y Y Encryption and compression functions Y Y Y Y Y Y Y Y Y Y Y Y Vector functions and operators E N N N N N N N N N N N Information

com/tidb/v8.2/system-variables#tidb_enable �→ _parallel_hashagg_spill-new-in-v800">The parallel HashAgg algorithm �→ of TiDB supports disk spill (GA) HashAgg is a widely used aggregation operator documentation. 38 • The parallel HashAgg algorithm of TiDB supports disk spill (GA) #35637 @xzhangxian1008 TiDB v8.0.0 introduces the parallel HashAgg algorithm with disk spill support as an experimental feature. In v8.2.0, this feature becomes generally available (GA). When using the parallel HashAgg algorithm, TiDB automatically triggers data spill based on memory usage, thus balancing query performance

g_spill system variable to control whether TiDB supports disk spill for the concurrent HashAgg algorithm. In future versions, the tidb_enable_parallel_hashagg_spill sys- tem variable will be deprecated operators Y Y Y Y Y Y Y Y Y Y Y Cast functions and operators Y Y Y Y Y Y Y Y Y Y Y Encryption and compression functions Y Y Y Y Y Y Y Y Y Y Y Information functions Y Y Y Y Y Y Y Y Y Y Y JSON functions Y 1 6.5 6.1 5.4 5.3 5.2 5.1 MPP execution engine Y Y Y Y Y Y Y Y Y Y Y MPP execution engine - compression exchange Y Y Y Y Y N N N N N N TiFlash Pipeline Model Y Y Y Y N N N N N N N TiFlash replica selection

experimental coarse-grained Region scatter �→ algorithm to accelerate snapshot restores for clusters. In clusters �→ with many TiKV nodes, this algorithm significantly improves cluster �→ resource efficiency downtime. Before v7.6.0, the Region scattering algorithm is a primary bottleneck in performance restoration. In v7.6.0, BR optimizes the Region scattering algorithm, which quickly splits the restore task into num- ber of small tasks and scatters them to all TiKV nodes in batches. The new parallel recovery algorithm fully utilizes the resources of each TiKV node, thereby achieving a rapid parallel recovery. In

and operators Y Y Y Y Y Y Y Y Y Cast functions and operators Y Y Y Y Y Y Y Y Y Encryption and compression functions Y Y Y Y Y Y Y Y Y Information functions Y Y Y Y Y Y Y Y Y JSON functions Y Y Y Y E Optimizer hints Y Y Y Y Y Y Y Y Y MPP execution engine Y Y Y Y Y Y Y Y Y MPP execution engine - compression exchange Y Y Y N N N N N N TiFlash Pipeline Model Y Y N N N N N N N TiFlash replica selection increment Y Y Y Y4 Y Y Y Y Y Auto random Y Y Y Y Y Y Y Y Y TTL (Time to Live) Y Y Y E N N N N N DDL algorithm assertions Y Y Y Y Y Y Y Y Y Multi-schema change: add columns Y Y Y Y E E E E E Change column type

configure blob- �→ cache-size separately. • Support dynamically modifying min-blob-size, blob-file-compression, and discardable-ratio to improve performance and flexibility when using the Titan engine. For significantly by implementing various optimizations such as adopting the coarse-grained Region scattering algorithm, creating databases and tables in batches, reducing the mutual impact between SST file downloads limited, it is recommended to use a finer-grained Region scattering algorithm. In addition, because the coarse-grained Region scattering algorithm might consume a significant amount of external storage bandwidth

�→ caching system, which provides a cache strategy based on the �→ Least Recently Used (LRU) algorithm for table metadata. It �→ prioritizes storing the metadata of frequently accessed tables in �→ the and operators Y Y Y Y Y Y Y Y Y Cast functions and operators Y Y Y Y Y Y Y Y Y Encryption and compression functions Y Y Y Y Y Y Y Y Y Information functions Y Y Y Y Y Y Y Y Y 58 Data types, functions Optimizer hints Y Y Y Y Y Y Y Y Y MPP execution engine Y Y Y Y Y Y Y Y Y MPP execution engine - compression exchange Y Y Y N N N N N N TiFlash Pipeline Model Y Y N N N N N N N TiFlash replica selection

incorrect results due to condition pushdown of CTEs #47881 @winoros • Fix the issue that the MySQL compression protocol cannot handle large loads of data (>=16M) #47152 #47157 #47161 @dveeden • Fix the issue operators Y Y Y Y Y Y Y Y Y Y Cast functions and operators Y Y Y Y Y Y Y Y Y Y Encryption and compression functions Y Y Y Y Y Y Y Y Y Y Information functions Y Y Y Y Y Y Y Y Y Y JSON functions Y Y Y Y N 62 Advanced SQL features 7.5 7.1 6.5 6.1 5.4 5.3 5.2 5.1 5.0 4.0 MPP execution engine - compression exchange Y Y N N N N N N N N TiFlash Pipeline Model Y N N N N N N N N N TiFlash replica selection

For more information, see documentation. • TiFlash supports automatically choosing an MPP Join algorithm according to the overhead of network transmission #7084 @solotzg The TiFlash MPP mode supports algorithms. Before v7.1.0, TiDB de- termines whether the MPP mode uses the Broadcast Hash Join algorithm based on the tidb_broadcast_join_threshold_count and tidb_broadcast_join_threshold_size �→ variables whether to choose the MPP Join algorithm based on the minimum overhead of network transmission. This variable is disabled by default, indicating that the default algorithm selection method remains the same