FLUSH TABLES

On this page

Completes all in-progress DDL and DML transactions (writes) that are running against any databases in the cluster. Then, for each database in the cluster, makes every table available for reads, but not writes.

Syntax

FLUSH TABLES [ON db_name] WITH READ {LOCK | ONLY}

Arguments

db_name: name of the database

Remarks

FLUSH TABLES WITH READ LOCK blocks any DDL and DML transactions (writes) that are initiated following the execution of the command.
FLUSH TABLES WITH READ ONLY fails any DDL and DML transactions (writes) that are initiated following the execution of the command, while holding the flush table locks.
If you have any pipelines currently running, SingleStore recommends to stop them before executing the FLUSH TABLES.. command. Do not create/drop/start/stop pipelines before executing the UNLOCK TABLES command.
Running UNLOCK TABLES after FLUSH TABLES... will make the cluster available for writes. Running UNLOCK TABLES after FLUSH TABLES WITH READ LOCK, specifically, will also unblock any writes that were initiated after FLUSH TABLES WITH READ LOCK was submitted. The UNLOCK TABLES query must be run in the same connection as the FLUSH TABLES query for this feature to take effect.
If the client connection that issued FLUSH TABLES... gets disconnected or is killed by an external process, then the lock is automatically released without the need to run the UNLOCK TABLES command.
This command causes implicit commits. Refer to COMMIT for more information.
Node Requirements for SingleStore Commands
Refer to the Permission Matrix for the required permission.

Example

SQL

FLUSH TABLES WITH READ LOCK;

UNLOCK TABLES

Last modified: March 8, 2024

Was this article helpful?

Verification instructions

Note: You must install cosign to verify the authenticity of the SingleStore file.

Use the following steps to verify the authenticity of singlestoredb-server, singlestoredb-toolbox, singlestoredb-studio, and singlestore-client SingleStore files that have been downloaded.

You may perform the following steps on any computer that can run cosign, such as the main deployment host of the cluster.

(Optional) Run the following command to view the associated signature files.
Shell
```
curl undefined
```
Download the signature file from the SingleStore release server.
- Option 1: Click the Download Signature button next to the SingleStore file.
- Option 2: Copy and paste the following URL into the address bar of your browser and save the signature file.
- Option 3: Run the following command to download the signature file.
  Shell
```
curl -O undefined
```

After the signature file has been downloaded, run the following command to verify the authenticity of the SingleStore file.

Shell

echo -n undefined |
    cosign verify-blob --certificate-oidc-issuer https://oidc.eks.us-east-1.amazonaws.com/id/CCDCDBA1379A5596AB5B2E46DCA385BC \
      --certificate-identity https://kubernetes.io/namespaces/freya-production/serviceaccounts/job-worker \
      --bundle undefined \
      --new-bundle-format -

Verified OK