Description Column Description read Data reading configuration write Data writing configuration stream_channel Data channel Example • Query migration rule SHOW MIGRATION RULE; mysql> SHOW MIGRATION -------------------+-------------------------------------------------------+ | read | write | stream_channel | +--------------------------------------------------------------+------------------- '=' batchSize ',')? ('SHARDING_SIZE' '=' shardingSize ',')? (rateLimiter)? ')' dataChannel ::= 'STREAM_CHANNEL' '(' 'TYPE' '(' 'NAME' '=' algorithmName ',' propertiesDefinition ')' ')' workerThreadPoolSize

Description Column Description read Data reading configuration write Data writing configuration stream_channel Data channel Example • Query migration rule SHOW MIGRATION RULE; mysql> SHOW MIGRATION -------------+ | read | write 9.2. ShardingSphere-Proxy 330 Apache ShardingSphere document | stream_channel | +--------------------------------------------------------------+------------------- '=' batchSize ',')? ('SHARDING_SIZE' '=' shardingSize ',')? (rateLimiter)? ')' dataChannel ::= 'STREAM_CHANNEL' '(' 'TYPE' '(' 'NAME' '=' algorithmName ',' propertiesDefinition ')' ')' workerThreadPoolSize

execution result sets to output through unified JDBC interface. Result merger in‐ cludes methods as stream merger, memory merger and addition merger using decorator merger. Parse Engine Compared to other without influencing the correctness of the query. It can be divided into single node optimization and stream merger optimization. Single Node Optimization It refers to the optimization that stops the SQL bandwidth. Stream Merger Optimization It only adds sorting items and sorting orders identical with grouping items and ORDER BY to GROUP BY SQL, and they are used to transfer memory merger to stream merger

rewrite. Optimization of ShardingSphere ShardingSphere has optimized in two ways. Firstly, it adopts stream process + merger ordering to avoid excessive memory occupation. SQL rewrite unavoidably occupies DATA_CONSISTENCY_CHECKER (algorithmDefinition) rateLimiter: RATE_LIMITER (algorithmDefinition) streamChannel: STREAM_CHANNEL (algorithmDefinition) workerThread: WORKER_THREAD=intValue batchSize: BATCH_SIZE=intValue WORKER_THREAD=40, BATCH_SIZE=1000 ), 5.2. ShardingSphere-Proxy 170 Apache ShardingSphere document, v5.1.1 STREAM_CHANNEL(TYPE(NAME=MEMORY, PROPERTIES("block-queue-size"=10000))), COMPLETION_DETECTOR(TYPE(NAME=IDLE

rewrite. Optimization of ShardingSphere ShardingSphere has optimized in two ways. Firstly, it adopts stream process + merger ordering to avoid excessive memory occupation. SQL rewrite unavoidably occupies DATA_CONSISTENCY_CHECKER (algorithmDefinition) rateLimiter: RATE_LIMITER (algorithmDefinition) streamChannel: STREAM_CHANNEL (algorithmDefinition) workerThread: WORKER_THREAD=intValue batchSize: BATCH_SIZE=intValue INPUT( WORKER_THREAD=40, BATCH_SIZE=1000 ), OUTPUT( WORKER_THREAD=40, BATCH_SIZE=1000 ), STREAM_CHANNEL(TYPE(NAME=MEMORY, PROPERTIES("block-queue-size"=10000))), COMPLETION_DETECTOR(TYPE(NAME=IDLE

-------------------+------------------------------------------------------+ | read | write | stream_channel | +--------------------------------------------------------------+------------------- WORKER_THREAD=40, BATCH_SIZE=1000, RATE_LIMITER (TYPE(NAME='TPS',PROPERTIES('tps'='2000'))) ), STREAM_CHANNEL (TYPE(NAME='MEMORY',PROPERTIES('block-queue-size'='10000'))) ); Configuration item description: property. 'tps'='2000' ))) ), 4.2. ShardingSphere-Proxy 250 Apache ShardingSphere document, v5.2.0 STREAM_CHANNEL ( -- Data channel. It connects producers and consumers, used for reading and writing procedures

-------------------+------------------------------------------------------+ | read | write | stream_channel | +--------------------------------------------------------------+------------------- WORKER_THREAD=40, BATCH_SIZE=1000, RATE_LIMITER (TYPE(NAME='TPS',PROPERTIES('tps'='2000'))) ), STREAM_CHANNEL (TYPE(NAME='MEMORY',PROPERTIES('block-queue-size'='10000'))) ); Configuration item description: property. 'tps'='2000' ))) ), 4.2. ShardingSphere-Proxy 258 Apache ShardingSphere document, v5.2.1 STREAM_CHANNEL ( -- Data channel. It connects producers and consumers, used for reading and writing procedures

rewrite. Optimization of ShardingSphere ShardingSphere has optimized in two ways. Firstly, it adopts stream process + merger ordering to avoid excessive memory occupation. SQL rewrite unavoidably occupies execution result sets to output through unified JDBC interface. Result merger in‐ cludes methods as stream merger, memory merger and addition merger using decorator merger. 7.1.6 Query Optimization Supported without influencing the correctness of the query. It can be divided into single node optimization and stream merger optimization. Single Node Optimization It refers to the optimization that stops the SQL

语法用于查询数据迁移规则。### 语法 ShowMigrationRule ::= 'SHOW' 'MIGRATION' 'RULE' 返回值说明 列 说明 read 数据读取配置 write 数据写入配置 stream_channel 数据通道 示例 • 查询数据迁移规则 SHOW MIGRATION RULE; mysql> SHOW MIGRATION RULE; +-------------- -------------------+-------------------------------------------------------+ | read | write | stream_channel | +--------------------------------------------------------------+------------------- '=' batchSize ',')? ('SHARDING_SIZE' '=' shardingSize ',')? (rateLimiter)? ')' dataChannel ::= 'STREAM_CHANNEL' '(' 'TYPE' '(' 'NAME' '=' algorithmName ',' propertiesDefinition ')' ')' workerThreadPoolSize

语法用于查询数据迁移规则。### 语法 ShowMigrationRule ::= 'SHOW' 'MIGRATION' 'RULE' 返回值说明 列 说明 read 数据读取配置 write 数据写入配置 stream_channel 数据通道 9.2. ShardingSphere-Proxy 292 Apache ShardingSphere document 示例 • 查询数据迁移规则 SHOW -------------------+-------------------------------------------------------+ | read | write | stream_channel | +--------------------------------------------------------------+------------------- (rateLimiter)? ')' 9.2. ShardingSphere-Proxy 293 Apache ShardingSphere document dataChannel ::= 'STREAM_CHANNEL' '(' 'TYPE' '(' 'NAME' '=' algorithmName ',' propertiesDefinition ')' ')' workerThreadPoolSize