---
title: dataset measure
versions:
  fpt: '*'
  ghae: '*'
  ghec: '*'
  ghes: '*'
topics:
  - Advanced Security
  - Code scanning
  - CodeQL
type: reference
product: '{% data reusables.gated-features.codeql %}'
autogenerated: codeql-cli
intro: |-
  [Plumbing] Collect statistics about the relations in a particular
  dataset.
redirect_from:
  - /code-security/codeql-cli/manual/dataset-measure
---


<!-- Content after this section is automatically generated -->

{% data reusables.codeql-cli.man-pages-version-note %}

## Synopsis

```shell copy
codeql dataset measure --output=<file> [--threads=<num>] <options>... -- <dataset>
```

## Description

\[Plumbing] Collect statistics about the relations in a particular
dataset.

This command is typically only used when developing a CodeQL extractor,
after a change that affects the database schema and which therefore
needs to have an accompanying change to the statistics used by the query
optimizer.

## Primary options

#### `<dataset>`

\[Mandatory] Path to the raw QL dataset to measure.

#### `-o, --output=<file>`

\[Mandatory] The output file to which statistics should be written,
typically with a '.dbscheme.stats' extension.

#### `-j, --threads=<num>`

The number of concurrent threads to use.

Defaults to 1. You can pass 0 to use one thread per core on the machine,
or -_N_ to leave _N_ cores unused (except still use at least one
thread).

### Common options

#### `-h, --help`

Show this help text.

#### `-J=<opt>`

\[Advanced] Give option to the JVM running the command.

(Beware that options containing spaces will not be handled correctly.)

#### `-v, --verbose`

Incrementally increase the number of progress messages printed.

#### `-q, --quiet`

Incrementally decrease the number of progress messages printed.

#### `--verbosity=<level>`

\[Advanced] Explicitly set the verbosity level to one of errors,
warnings, progress, progress+, progress++, progress+++. Overrides `-v`
and `-q`.

#### `--logdir=<dir>`

\[Advanced] Write detailed logs to one or more files in the given
directory, with generated names that include timestamps and the name of
the running subcommand.

(To write a log file with a name you have full control over, instead
give `--log-to-stderr` and redirect stderr as desired.)