Using the Scalar Execution Engine

The default and recommended SQL engine in this release is the Vectorized Execution Engine (VEE). The legacy Scalar Execution Engine (SEE) can be enabled in the following ways:

Upgrading from a previous release

Choose either,

  1. Set the default execution-engine database option when starting all Transaction Engines (TEs) using nuocmd start process. Use the command switch --options execution-engine scalar to force all connections to a TE to use SEE unless overridden by the connection property SQLEngine=vee.
    See Database Options for more information.

  2. Set the SQLEngine=scalar connection property to enable it on a per-connection basis. This will override the default vee execution engine.
    See Connection Properties for more information.

Create a new database

Set the default execution-engine database option at database create time using nuocmd create database. Use the command switch --default-options execution-engine scalar to force all TEs to start with SEE as the default SQL execution engine. No further changes or settings are required to use SEE.

Modify an already running database

If a running database is using VEE and you would like it to switch to SEE, update the default execution-engine database option to scalar and restart the database processes. To update the database default options, use nuocmd update database-options with the --default-options execution-engine scalar option.

This change will only take effect for TEs you start after running this command. It does not apply to TEs that are already running.

Therefore, restart the database TE processes using nuocmd start process to complete the change to the scalar execution engine.