Query Store settings

Query Store settings#

List of Querona’s Query Store settings:

Configuration option

Default value

Requires restart?

Description

Archived Record Age Max

4

No

Archived statement expiration interval (aka. max age), after which statement will be purged. 0 indicates no limit (not recommended). Default value is in days.

Buffer Capacity

8000

Yes

Maximum capacity of buffer that holds completed statements ready for storing.

Buffer Full Mode

DropOldest

Yes

Behavior of the buffer when the buffer is full and new items arrive.

Supported values are:

  • Wait - Wait for space to be available in order to complete the write operation.

  • DropNewest - Remove and ignore the newest item in order to make room for the item being written.

  • DropOldest - Remove and ignore the oldest item in order to make room for the item being written.

  • DropWrite - Drop the item being written.

Buffer FlushMode

Batch

Flush mode for the QueryStore’s statement buffer. This property determines how the buffer is flushed during runtime.

Supported values are:

  • Disabled - Flushing is disabled.

  • Batch - Statements are flushed in batches for better performance, utilizing bulk operations in the underlying engine. If engine does not support batches, falls back to Single.

  • Single - Each statement is flushed individually.

Checkpoint Interval

6

No

Interval of flushing a completed statement buffer to database (checkpoint), in seconds.

Capture Mode

Auto

No

The capture mode determines which queries are captured by the Query Store.

Supported values are:

  • All - Captures all queries.

  • Auto - Captures queries based on internal algorithm for decision-making.

  • None - Disables query capturing.

  • Custom - Captures queries based on configured policy.

Capture Policy Query Duration Min

0

No

A filter on statement duration that get accepted for saving.

Capture Policy Query Status

All

No

A single-value filter on statement status that get accepted for saving.

Supported values are:

  • All - All statements are captured.

  • Success - Only successful statements are captured.

  • Failure - Only failed statements are captured.

Enabled

False

Yes

Controls whether Query Store functionality is enabled. True if the Query Store is enabled, otherwise, False.

Runtime Max Storage Size Mb

100

Yes

Gets or sets the maximum storage size, in megabytes, allocated for the runtime engine.

Runtime Engine Name

SqLite

Yes

Database engine used by the Query Store to store data at runtime.

Runtime Engine Connection String

Tes

Connection string used by the selected Query Store runtime storage engine.

The connection string is database-engine specific and includes settings such as memory limits.

Environment variables can be used within the connection string and will be expanded at runtime. Replacement only occurs for environment variables that are set, otherwise the variable name remains unchanged.

The default value points to a SqLite database file located in the %QUERONA_HOME% directory.

Example connection string for SqLite database:

Data Source=%QUERONA_HOME%\querona-querystore.db;Journal Mode=WAL;max_memory='512MB'

Note

Currently, only SqLite engine is supported as Query Store’s storage engine.