Class: ScanPolicy

ScanPolicy

A policy affecting the behavior of scan operations.


new ScanPolicy( [props])

Initializes a new ScanPolicy from the provided policy values.

Parameters:
Name Type Argument Description
props Object <optional>

Policy values

Since:
  • v3.0.0
Source:

Extends

Members


compress :boolean

Use zlib compression on write or batch read commands when the command buffer size is greater than 128 bytes. In addition, tell the server to compress it's response on read commands. The server response compression threshold is also 128 bytes.

This option will increase cpu and memory usage (for extra compressed buffers), but decrease the size of data sent over the network.

Requires Enterprise Server version >= 4.8.

Type:
  • boolean
Since:
  • v3.14.0
Inherited From:
Overrides:
Source:

durableDelete :boolean

Specifies whether a tombstone should be written in place of a record that gets deleted as a result of this operation.

Type:
  • boolean
Default Value:
  • false (do not tombstone deleted records)
Source:

filterExpression

Optional expression filter. If filter exp exists and evaluates to false, the transaction is ignored. This can be used to eliminate a client/server roundtrip in some cases.

expression filters can only be applied to the following commands:

Inherited From:
Overrides:
Source:

maxRecords :number

Approximate number of records to return to client. This number is divided by the number of nodes involved in the scan. The actual number of records returned may be less than maxRecords if node record counts are small and unbalanced across nodes.

Requires server >= 4.9.

Type:
  • number
Since:
  • v3.16.0
Default Value:
  • 0 (do not limit record count)
Source:

maxRetries :number

Maximum number of retries before aborting the current transaction. The initial attempt is not counted as a retry.

If maxRetries is exceeded, the transaction will return error ERR_TIMEOUT.

WARNING: Database writes that are not idempotent (such as "add") should not be retried because the write operation may be performed multiple times if the client timed out previous transaction attempts. It is important to use a distinct write policy for non-idempotent writes which sets maxRetries to zero.

Type:
  • number
Inherited From:
Overrides:
Source:

recordsPerSecond :number

Limit returned records per second (RPS) rate for each server. Do not apply RPS limit if recordsPerSecond is zero.

Requires server >= 4.7.

Type:
  • number
Since:
  • v3.14.0
Default Value:
  • 0
Source:

socketTimeout :number

Socket idle timeout in milliseconds when processing a database command.

If socketTimeout is not zero and the socket has been idle for at least socketTimeout, both maxRetries and totalTimeout are checked. If maxRetries and totalTimeout are not exceeded, the transaction is retried.

If both socketTimeout and totalTimeout are non-zero and socketTimeout > totalTimeout, then socketTimeout will be set to totalTimeout. If socketTimeout is zero, there will be no socket idle limit.

Type:
  • number
Inherited From:
Overrides:
Default Value:
  • 0 (no socket idle time limit).
Source:

totalTimeout :number

Total transaction timeout in milliseconds.

The totalTimeout is tracked on the client and sent to the server along with the transaction in the wire protocol. The client will most likely timeout first, but the server also has the capability to timeout the transaction.

If totalTimeout is not zero and totalTimeout is reached before the transaction completes, the transaction will return error ERR_TIMEOUT. If totalTimeout is zero, there will be no total time limit.

Type:
  • number
Inherited From:
Overrides:
Default Value:
  • 1000
Source: