---
title: dataset measure
versions: # DO NOT MANUALLY EDIT. CHANGES WILL BE OVERWRITTEN BY A 🤖
  fpt: '*'
  ghec: '*'
  ghes: '*'
topics:
  - Code 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
---

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{% 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.

## Options

### 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.)

#### `--common-caches=<dir>`

\[Advanced] Controls the location of cached data on disk that will
persist between several runs of the CLI, such as downloaded QL packs and
compiled query plans. If not set explicitly, this defaults to a
directory named `.codeql` in the user's home directory; it will be
created if it doesn't already exist.

Available since `v2.15.2`.