SHOW RULE [FROM tablename]
使用说明:
-
show rule
:查看数据库下每一个逻辑表的拆分情况; -
show rule from tablename
:查看数据库下指定逻辑表的拆分情况。
mysql> show rule; +----+------------+-----------+------------------+---------------------+--------------------+------------------+---------------------+--------------------+ | ID | TABLE_NAME | BROADCAST | DB_PARTITION_KEY | DB_PARTITION_POLICY | DB_PARTITION_COUNT | TB_PARTITION_KEY | TB_PARTITION_POLICY | TB_PARTITION_COUNT | +----+------------+-----------+------------------+---------------------+--------------------+------------------+---------------------+--------------------+ | 0 | k_1 | 0 | k | hash | 40 | k | hash | 2 | | 1 | k_2 | 0 | k | hash | 40 | k | hash | 2 | | 2 | sbtest1 | 0 | id | hash | 40 | id | hash | 2 | | 3 | t1 | 0 | id | hash | 40 | id | hash | 4 | +----+------------+-----------+------------------+---------------------+--------------------+------------------+---------------------+--------------------+ 4 rows in set (0.05 sec)
重要列详解:
- BROADCAST:是否为广播表(0:否,1:是);
- DB_PARTITION_KEY:分库的拆分键,没有分库的话,值为空;
- DB_PARTITION_POLICY:分库的拆分策略,取值包括哈希或YYYYMM、YYYYDD、YYYYWEEK等日期策略;
- DB_PARTITION_COUNT:分库数;
- TB_PARTITION_KEY:分表的拆分键,没有分表的话,值为空;
- TB_PARTITION_POLICY:分表的拆分策略,取值包括哈希或MM、DD、MMDD、WEEK等日期策略;
- TB_PARTITION_COUNT:分表数。
SHOW FULL RULE [FROM tablename]
查看数据库下逻辑表的拆分规则,比SHOW RULE指令展示的信息更加详细。
mysql> show full rule; +----+------------+-----------+------------+-----------------------+----------------------+--------------------------------------------------+-------------------+----------------------------------------+----------------+--------------------+ | ID | TABLE_NAME | BROADCAST | JOIN_GROUP | ALLOW_FULL_TABLE_SCAN | DB_NAME_PATTERN | DB_RULES_STR | TB_NAME_PATTERN | TB_RULES_STR | PARTITION_KEYS | DEFAULT_DB_INDEX | +----+------------+-----------+------------+-----------------------+----------------------+--------------------------------------------------+-------------------+----------------------------------------+----------------+--------------------+ | 0 | k_1 | 0 | NULL | 1 | TEST1_{000000}_GROUP | ((#k,1,80#).longValue().abs() % 80).intdiv(2) | k_1_cewR_{00} | ((#k,1,80#).longValue().abs() % 80) | k | TEST1_SINGLE_GROUP | | 1 | k_2 | 0 | NULL | 1 | TEST1_{000000}_GROUP | ((#k,1,80#).longValue().abs() % 80).intdiv(2) | k_2_1xsQ_{00} | ((#k,1,80#).longValue().abs() % 80) | k | TEST1_SINGLE_GROUP | | 2 | sbtest1 | 0 | NULL | 1 | TEST1_{000000}_GROUP | ((#id,1,80#).longValue().abs() % 80).intdiv(2) | sbtest1_wO5k_{00} | ((#id,1,80#).longValue().abs() % 80) | id | TEST1_SINGLE_GROUP | | 3 | t1 | 0 | NULL | 1 | TEST1_{000000}_GROUP | ((#id,1,160#).longValue().abs() % 160).intdiv(4) | t1_EMrC_{000} | ((#id,1,160#).longValue().abs() % 160) | id | TEST1_SINGLE_GROUP | +----+------------+-----------+------------+-----------------------+----------------------+--------------------------------------------------+-------------------+----------------------------------------+----------------+--------------------+
重要列详解:
- BROADCAST:是否为广播表(0:否,1:是);
- JOIN_GROUP:保留字段,暂时无意义。
- ALLOW_FULL_TABLE_SCAN:分库分表在没有指定分表键值的情况下是否允许查询数据,如果配置为true,此时需要扫描每一个物理表来查找出符合条件的数据,简称为全表扫描;
- DB_NAME_PATTERN:DB_NAME_PATTERN中{}之间的0为占位符,执行SQL时会被DB_RULES_STR计算出的值替代,并保持位数。比如,DB_NAME_PATTERN的值为SEQ_{0000}_RDS,DB_RULES_STR的值为[1,2,3,4],则会产生4个DB_NAME,分别为SEQ_0001_RDS、SEQ_0002_RDS、SEQ_0003_RDS、SEQ_0004_RDS;
- DB_RULES_STR:具体的分库规则;
- TB_NAME_PATTERN:TB_NAME_PATTERN中{}之间的0为占位符,执行SQL时会被TB_RULES_STR计算出的值替代,并保持位数。比如,TB_NAME_PATTERN的值为table_{00},TB_RULES_STR的值为[1,2,3,4,5,6,7,8],则会产生8张表,分别为table_01、table_02、table_03、table_04、table_05、table_06、table_07、table_08;
- TB_RULES_STR:分表规则;
- PARTITION_KEYS:分库和分表键集合,对于既分库又分表的情形,分库键在前,分表键在后;
- DEFAULT_DB_INDEX:单库单表存放的分库。
SHOW TOPOLOGY FROM tablename
查看指定逻辑表的拓扑分布,展示该逻辑表保存在哪些分库中,每个分库下包含哪些分表。
mysql> show topology from emp; +------+--------------------------------------------------+------------+ | ID | GROUP_NAME | TABLE_NAME | +------+--------------------------------------------------+------------+ | 0 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0000_RDS | emp_0 | | 1 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0000_RDS | emp_1 | | 2 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0001_RDS | emp_0 | | 3 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0001_RDS | emp_1 | | 4 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0002_RDS | emp_0 | | 5 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0002_RDS | emp_1 | | 6 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0003_RDS | emp_0 | | 7 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0003_RDS | emp_1 | | 8 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0004_RDS | emp_0 | | 9 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0004_RDS | emp_1 | | 10 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0005_RDS | emp_0 | | 11 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0005_RDS | emp_1 | | 12 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0006_RDS | emp_0 | | 13 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0006_RDS | emp_1 | | 14 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0007_RDS | emp_0 | | 15 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0007_RDS | emp_1 | +------+--------------------------------------------------+------------+
SHOW PARTITIONS FROM tablename
查看分库分表键集合,分库键和分表键之间用逗号分割。如果最终结果有两个值,说明是既分库又分表的情形,第一个是分库键,第二个是分表键。如果结果只有一个值,说明是分库不分表的情形,该值是分库键。
mysql> show partitions from emp; +-----------+ | KEYS | +-----------+ | emp_no,id | +-----------+ 1 row in set (0.00 sec)
SHOW BROADCASTS
查看广播表列表。
mysql> show broadcasts; +------+------------+ | ID | TABLE_NAME | +------+------------+ | 0 | brd2 | | 1 | brd_tbl | +------+------------+ 2 rows in set (0.01 sec)
SHOW DATASOURCES
查看底层存储信息,包含数据库名、数据库分组名、连接信息、用户名、底层存储类型、读写权重、连接池信息等。
mysql> show datasources; +------+----------------------------+------------------------------------------------+--------------------------------------------------+----------------------------------------------------------------------------------+-----------+-------+------+------+------+--------------+----------+--------------+---------------+----------------------------------------------+-------------+--------------+ | ID | SCHEMA | NAME | GROUP | URL | USER | TYPE | INIT | MIN | MAX | IDLE_TIMEOUT | MAX_WAIT | ACTIVE_COUNT | POOLING_COUNT | ATOM | READ_WEIGHT | WRITE_WEIGHT | +------+----------------------------+------------------------------------------------+--------------------------------------------------+----------------------------------------------------------------------------------+-----------+-------+------+------+------+--------------+----------+--------------+---------------+----------------------------------------------+-------------+--------------+ | 0 | seq_test_1487767780814rgkk | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0000_iiab_1 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0000_RDS | jdbc:mysql://rds1ur80kcv8g3t6p3ol.mysql.rds.aliyuncs.com:3306/seq_test_wnjg_0000 | jnkinsea0 | mysql | 0 | 24 | 72 | 15 | 5000 | 0 | 1 | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0000_iiab | 10 | 10 | | 1 | seq_test_1487767780814rgkk | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0001_iiab_2 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0001_RDS | jdbc:mysql://rds1ur80kcv8g3t6p3ol.mysql.rds.aliyuncs.com:3306/seq_test_wnjg_0001 | jnkinsea0 | mysql | 0 | 24 | 72 | 15 | 5000 | 0 | 1 | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0001_iiab | 10 | 10 | | 2 | seq_test_1487767780814rgkk | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0002_iiab_3 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0002_RDS | jdbc:mysql://rds1ur80kcv8g3t6p3ol.mysql.rds.aliyuncs.com:3306/seq_test_wnjg_0002 | jnkinsea0 | mysql | 0 | 24 | 72 | 15 | 5000 | 0 | 1 | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0002_iiab | 10 | 10 | | 3 | seq_test_1487767780814rgkk | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0003_iiab_4 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0003_RDS | jdbc:mysql://rds1ur80kcv8g3t6p3ol.mysql.rds.aliyuncs.com:3306/seq_test_wnjg_0003 | jnkinsea0 | mysql | 0 | 24 | 72 | 15 | 5000 | 0 | 1 | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0003_iiab | 10 | 10 | | 4 | seq_test_1487767780814rgkk | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0004_iiab_5 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0004_RDS | jdbc:mysql://rds1ur80kcv8g3t6p3ol.mysql.rds.aliyuncs.com:3306/seq_test_wnjg_0004 | jnkinsea0 | mysql | 0 | 24 | 72 | 15 | 5000 | 0 | 1 | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0004_iiab | 10 | 10 | | 5 | seq_test_1487767780814rgkk | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0005_iiab_6 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0005_RDS | jdbc:mysql://rds1ur80kcv8g3t6p3ol.mysql.rds.aliyuncs.com:3306/seq_test_wnjg_0005 | jnkinsea0 | mysql | 0 | 24 | 72 | 15 | 5000 | 0 | 1 | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0005_iiab | 10 | 10 | | 6 | seq_test_1487767780814rgkk | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0006_iiab_7 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0006_RDS | jdbc:mysql://rds1ur80kcv8g3t6p3ol.mysql.rds.aliyuncs.com:3306/seq_test_wnjg_0006 | jnkinsea0 | mysql | 0 | 24 | 72 | 15 | 5000 | 0 | 1 | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0006_iiab | 10 | 10 | | 7 | seq_test_1487767780814rgkk | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0007_iiab_8 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0007_RDS | jdbc:mysql://rds1ur80kcv8g3t6p3ol.mysql.rds.aliyuncs.com:3306/seq_test_wnjg_0007 | jnkinsea0 | mysql | 0 | 24 | 72 | 15 | 5000 | 0 | 1 | rds1ur80kcv8g3t6p3ol_seq_test_wnjg_0007_iiab | 10 | 10 | +------+----------------------------+------------------------------------------------+--------------------------------------------------+----------------------------------------------------------------------------------+-----------+-------+------+------+------+--------------+----------+--------------+---------------+----------------------------------------------+-------------+--------------+
重要列详解:
- SCHEMA:数据库名;
- GROUP:数据库分组名。分组的目标是管理多组数据完全相同的数据库,比如通过 RDS(MySQL)进行数据复制后的主备数据库。主要用来解决读写分离、主备切换的问题;
- URL:底层RDS(MySQL)的连接信息;
- TYPE:底层存储类型,目前只支持RDS(MySQL);
- READ_WEIGHT:读权重。在主实例的读压力比较大的时候,可以通过读写分离功能将读流量进行分流,减轻RDS主实例的压力。PolarDB-X会自动识别读写流量,引导写流量进入RDS主实例,读流量则按配置的权重流向所有RDS实例;
- WRITE_WEIGHT:写权重。
SHOW NODE
查看物理库的读写次数(历史累计数据)、读写权重(历史累计数据)。
mysql> show node; +------+--------------------------------------------------+-------------------+------------------+---------------------+--------------------+ | ID | NAME | MASTER_READ_COUNT | SLAVE_READ_COUNT | MASTER_READ_PERCENT | SLAVE_READ_PERCENT | +------+--------------------------------------------------+-------------------+------------------+---------------------+--------------------+ | 0 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0000_RDS | 12 | 0 | 100% | 0% | | 1 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0001_RDS | 0 | 0 | 0% | 0% | | 2 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0002_RDS | 0 | 0 | 0% | 0% | | 3 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0003_RDS | 0 | 0 | 0% | 0% | | 4 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0004_RDS | 0 | 0 | 0% | 0% | | 5 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0005_RDS | 0 | 0 | 0% | 0% | | 6 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0006_RDS | 0 | 0 | 0% | 0% | | 7 | SEQ_TEST_1487767780814RGKKSEQ_TEST_WNJG_0007_RDS | 0 | 0 | 0% | 0% | +------+--------------------------------------------------+-------------------+------------------+---------------------+--------------------+ 8 rows in set (0.01 sec)
重要列详解:
- MASTER_COUNT:RDS主实例处理的读写查询次数(历史累计数据);
- SLAVE_COUNT:RDS备实例处理的只读查询次数(历史累计数据);
- MASTER_PERCENT:RDS主实例处理的读写查询占比(注意该列显示的是累计的实际数据占比,并不是用户配置的百分比);
- SLAVE_PERCENT:RDS备实例处理的读写查询占比(注意该列显示的是累计的实际数据占比,并不是用户配置的百分比)。
说明
- 事务中的只读查询会被发送到RDS主实例;
- 由于
MASTER_PERCENT
,SLAVE_PERCENT
这两列代表的是历史累计数据,更改读写权重的配比后,这几个数值并不能立即反应最新的读写权重配比,需累计一段比较长的时间才行。