- TSDB_PAGESIZE: The page size of the data storage engine in a vnode. The unit is KB. The default is 4 KB. The range is 1 to 16384, that is, 1 KB to 16 MB.
- WAL_RETENTION_PERIOD: specifies the maximum time of which WAL files are to be kept for consumption. This parameter is used for data subscription. Enter a time in seconds. The default value 0. A value of 0 indicates that WAL files are not required to keep for consumption. Alter it with a proper value at first to create topics.
- WAL_RETENTION_SIZE: specifies the maximum total size of which WAL files are to be kept for consumption. This parameter is used for data subscription. Enter a size in KB. The default value is 0. A value of 0 indicates that the total size of WAL files to keep for consumption has no upper limit.
- WAL_ROLL_PERIOD: specifies the time after which WAL files are rotated. After this period elapses, a new WAL file is created. The default value is 0. A value of 0 indicates that a new WAL file is created only after TSDB data in memory are flushed to disk.
- WAL_SEGMENT_SIZE: specifies the maximum size of a WAL file. After the current WAL file reaches this size, a new WAL file is created. The default value is 0. A value of 0 indicates that a new WAL file is created only after TSDB data in memory are flushed to disk.
@@ -100,12 +100,10 @@ Provides information about user-created databases. Similar to SHOW DATABASES.
| 23 | wal_fsync_period | INT | Interval at which WAL is written to disk. It should be noted that `wal_fsync_period` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 24 | wal_retention_period | INT | WAL retention period. It should be noted that `wal_retention_period` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 25 | wal_retention_size | INT | Maximum WAL size. It should be noted that `wal_retention_size` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 26 | wal_roll_period | INT | WAL rotation period. It should be noted that `wal_roll_period` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 27 | wal_segment_size | BIGINT | WAL file size. It should be noted that `wal_segment_size` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 28 | stt_trigger | SMALLINT | The threshold for number of files to trigger file merging. It should be noted that `stt_trigger` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 29 | table_prefix | SMALLINT | The prefix length in the table name that is ignored when distributing table to vnode based on table name. It should be noted that `table_prefix` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 30 | table_suffix | SMALLINT | The suffix length in the table name that is ignored when distributing table to vnode based on table name. It should be noted that `table_suffix` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 31 | tsdb_pagesize | INT | The page size for internal storage engine, its unit is KB. It should be noted that `tsdb_pagesize` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 26 | stt_trigger | SMALLINT | The threshold for number of files to trigger file merging. It should be noted that `stt_trigger` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 27 | table_prefix | SMALLINT | The prefix length in the table name that is ignored when distributing table to vnode based on table name. It should be noted that `table_prefix` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 28 | table_suffix | SMALLINT | The suffix length in the table name that is ignored when distributing table to vnode based on table name. It should be noted that `table_suffix` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
| 29 | tsdb_pagesize | INT | The page size for internal storage engine, its unit is KB. It should be noted that `tsdb_pagesize` is a TDengine keyword and needs to be escaped with ` when used as a column name. |
@@ -33,7 +33,7 @@ The following data types can be used in the schema for standard tables.
| 6 | ALTER USER | Modified | Deprecated<ul><li>PRIVILEGE: Specified user permissions. Replaced by GRANT and REVOKE. <br/>Added</li><li>ENABLE: Enables or disables a user. </li><li>SYSINFO: Specifies whether a user can query system information. </li></ul>
| 7 | COMPACT VNODES | Not supported | Compacted the data on a vnode. Not supported.
| 8 | CREATE ACCOUNT | Deprecated| This Enterprise Edition-only statement has been removed. It returns the error "This statement is no longer supported."
| 9 | CREATE DATABASE | Modified | Deprecated<ul><li>BLOCKS: Specified the number of blocks for each vnode. BUFFER is now used to specify the size of the write cache pool for each vnode. </li><li>CACHE: Specified the size of the memory blocks used by each vnode. BUFFER is now used to specify the size of the write cache pool for each vnode. </li><li>CACHELAST: Specified how to cache the newest row of data. CACHEMODEL now replaces CACHELAST. </li><li>DAYS: The length of time to store in a single file. Replaced by DURATION. </li><li>FSYNC: Specified the fsync interval when WAL was set to 2. Replaced by WAL_FSYNC_PERIOD. </li><li>QUORUM: Specified the number of confirmations required. STRICT is now used to specify strong or weak consistency. </li><li>UPDATE: Specified whether update operations were supported. All databases now support updating data in certain columns. </li><li>WAL: Specified the WAL level. Replaced by WAL_LEVEL. <br/>Added</li><li>BUFFER: Specifies the size of the write cache pool for each vnode. </li><li>CACHEMODEL: Specifies whether to cache the latest subtable data. </li><li>CACHESIZE: Specifies the size of the cache for the newest subtable data. </li><li>DURATION: Replaces DAYS. Now supports units. </li><li>PAGES: Specifies the number of pages in the metadata storage engine cache on each vnode. </li><li>PAGESIZE: specifies the size (in KB) of each page in the metadata storage engine cache on each vnode. </li><li>RETENTIONS: Specifies the aggregation interval and retention period </li><li>STRICT: Specifies whether strong data consistency is enabled. </li><li>SINGLE_STABLE: Specifies whether a database can contain multiple supertables. </li><li>VGROUPS: Specifies the initial number of vgroups when a database is created. </li><li>WAL_FSYNC_PERIOD: Replaces the FSYNC parameter. </li><li>WAL_LEVEL: Replaces the WAL parameter. </li><li>WAL_RETENTION_PERIOD: specifies the time after which WAL files are deleted. This parameter is used for data subscription. </li><li>WAL_RETENTION_SIZE: specifies the size at which WAL files are deleted. This parameter is used for data subscription. </li><li>WAL_ROLL_PERIOD: Specifies the WAL rotation period. </li><li>WAL_SEGMENT_SIZE: specifies the maximum size of a WAL file. <br/>Modified</li><li>KEEP: Now supports units. </li></ul>
| 9 | CREATE DATABASE | Modified | Deprecated<ul><li>BLOCKS: Specified the number of blocks for each vnode. BUFFER is now used to specify the size of the write cache pool for each vnode. </li><li>CACHE: Specified the size of the memory blocks used by each vnode. BUFFER is now used to specify the size of the write cache pool for each vnode. </li><li>CACHELAST: Specified how to cache the newest row of data. CACHEMODEL now replaces CACHELAST. </li><li>DAYS: The length of time to store in a single file. Replaced by DURATION. </li><li>FSYNC: Specified the fsync interval when WAL was set to 2. Replaced by WAL_FSYNC_PERIOD. </li><li>QUORUM: Specified the number of confirmations required. STRICT is now used to specify strong or weak consistency. </li><li>UPDATE: Specified whether update operations were supported. All databases now support updating data in certain columns. </li><li>WAL: Specified the WAL level. Replaced by WAL_LEVEL. <br/>Added</li><li>BUFFER: Specifies the size of the write cache pool for each vnode. </li><li>CACHEMODEL: Specifies whether to cache the latest subtable data. </li><li>CACHESIZE: Specifies the size of the cache for the newest subtable data. </li><li>DURATION: Replaces DAYS. Now supports units. </li><li>PAGES: Specifies the number of pages in the metadata storage engine cache on each vnode. </li><li>PAGESIZE: specifies the size (in KB) of each page in the metadata storage engine cache on each vnode. </li><li>RETENTIONS: Specifies the aggregation interval and retention period </li><li>STRICT: Specifies whether strong data consistency is enabled. </li><li>SINGLE_STABLE: Specifies whether a database can contain multiple supertables. </li><li>VGROUPS: Specifies the initial number of vgroups when a database is created. </li><li>WAL_FSYNC_PERIOD: Replaces the FSYNC parameter. </li><li>WAL_LEVEL: Replaces the WAL parameter. </li><li>WAL_RETENTION_PERIOD: specifies the time after which WAL files are deleted. This parameter is used for data subscription. </li><li>WAL_RETENTION_SIZE: specifies the size at which WAL files are deleted. This parameter is used for data subscription. <br/>Modified</li><li>KEEP: Now supports units. </li></ul>
| 10 | CREATE DNODE | Modified | Now supports specifying hostname and port separately<ul><li>CREATE DNODE dnode_host_name PORT port_val</li></ul>
| 11 | CREATE INDEX | Added | Creates an SMA index.
| 6 | ALTER USER | 调整 | 废除<ul><li>PRIVILEGE：修改用户权限。3.0版本使用GRANT和REVOKE来授予和回收权限。<br/>新增</li><li>ENABLE：启用或停用此用户。</li><li>SYSINFO：修改用户是否可查看系统信息。</li></ul>
