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SHOW DATABASES
Shows the list of databases that exist on this MemSQL instance.
Syntax
SHOW DATABASES [EXTENDED]
[LIKE 'pattern']
Remarks
- The
EXTENDEDsuffix is a MemSQL-only extension that displays extra information about each database. - This command must be run on the master aggregator or a child aggregator node (see Node Requirements for MemSQL Commands).
Output (EXTENDED option)
| Column | Description |
|---|---|
Database |
Name of a database in the MemSQL instance |
Commits |
Number of committed transactions |
Role |
Database replication role |
State |
Current state (Database States) |
Position |
Current position in the transaction log in memory, formatted as <LogFileId>:<ByteOffsetInLogFile> |
Details |
Optional message about the current state |
AsyncSlaves |
Number of currently attached asynchronous replicas |
SyncSlaves |
Number of currently attached synchronous replicas |
ConsensusSlaves |
Number of currently attached replicas running in consensus mode |
CommittedPosition |
Position up to which each transaction has been committed |
HardenedPosition |
Current position in the transaction log on disk |
ReplayPosition |
Position to which changes have been applied to replica |
Term |
A unique identifier of the current master instance of the database |
LastPageTerm |
Term of the master that wrote the contents of the most recent page in the log that the secondary instance is aware of the database |
Memory (MBs) |
Memory used by the database |
Pending IOs |
Number of transaction log pages (of size 4KB each) that are waiting to be persisted to disk |
Examples
SHOW DATABASES;
****
+--------------------+
| Database |
+--------------------+
| cluster |
| memsql_demo |
| information_schema |
| memsql |
+--------------------+
SHOW DATABASES EXTENDED;
****
+--------------------+---------+--------+--------+----------+---------+-------------+------------+-----------------+-------------------+------------------+----------------+------+--------------+--------------+-------------+
| Database | Commits | Role | State | Position | Details | AsyncSlaves | SyncSlaves | ConsensusSlaves | CommittedPosition | HardenedPosition | ReplayPosition | Term | LastPageTerm | Memory (MBs) | Pending IOs |
+--------------------+---------+--------+--------+----------+---------+-------------+------------+-----------------+-------------------+------------------+----------------+------+--------------+--------------+-------------+
| cluster | 0 | master | online | 0:130 | | 1 | 0 | 0 | 0:130 | 0:130 | NULL | 24 | 0 | 0.00 | 0 |
| memsql_demo | 0 | master | online | 0:269 | | 1 | 0 | 0 | 0:269 | 0:269 | NULL | 21 | 0 | 0.00 | 0 |
| information_schema | 0 | master | online | 0:1 | | 0 | 0 | 0 | 0:1 | 0:1 | NULL | 2 | 0 | 0.00 | 0 |
| memsql | 0 | master | online | 0:408 | | 0 | 0 | 0 | 0:408 | 0:408 | NULL | 24 | 0 | 0.00 | 0 |
+--------------------+---------+--------+--------+----------+---------+-------------+------------+-----------------+-------------------+------------------+----------------+------+--------------+--------------+-------------+
