Update a database

Use the influxctl database update command to update a database in your {{< product-name omit=" Clustered" >}} cluster.

1. If you haven't already, download and install the influxctl CLI.

2. Run the influxctl database update command and provide the following:

   • Database name
   • Optional: Database retention period. Default is infinite (0).
   • Optional: Database table (measurement) limit. Default is 500.
   • Optional: Database column limit. Default is 250.

{{% code-placeholders "DATABASE_NAME|30d|500|200" %}}

influxctl database update \
  --retention-period 30d \
  --max-tables 500 \
  --max-columns 250 \
  DATABASE_NAME

{{% /code-placeholders %}}

Replace the following in your command:

• {{% code-placeholder-key %}}DATABASE_NAME{{% /code-placeholder-key %}}: your {{% product-name %}} database

[!Note]

Database names can't be updated with this command

The influxctl database update command uses the database name to identify which database to apply updates to. To rename a database, use the influxctl database rename command.

Database attributes

• Retention period syntax
• Database naming restrictions
• InfluxQL DBRP naming convention
• Table and column limits

Retention period syntax (influxctl CLI)

Use the --retention-period flag to define a specific retention period for the database. The retention period value is a time duration value made up of a numeric value plus a duration unit. For example, 30d means 30 days. A zero duration (for example, 0s or 0d) retention period is infinite and data won't expire. The retention period value cannot be negative or contain whitespace.

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Valid durations units include

• m: minute
• h: hour
• d: day
• w: week
• mo: month
• y: year

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Example retention period values

• 0d: infinite/none
• 3d: 3 days
• 6w: 6 weeks
• 1mo: 1 month (30 days)
• 1y: 1 year
• 30d30d: 60 days
• 2.5d: 60 hours

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Database naming restrictions

Database names must adhere to the following naming restrictions:

• Cannot contain whitespace, punctuation, or special characters. Only alphanumeric, underscore (_), dash (-), and forward-slash (/) characters are permitted.
• Should not start with an underscore (_).
• Maximum length of 64 characters.

InfluxQL DBRP naming convention

In InfluxDB 1.x, data is stored in databases and retention policies. In {{< product-name >}}, databases and retention policies have been merged into databases, where databases have a retention period, but retention policies are no longer part of the data model. Because InfluxQL uses the 1.x data model, a database must be mapped to a v1 database and retention policy (DBRP) to be queryable with InfluxQL.

When naming a database that you want to query with InfluxQL, use the following naming convention to automatically map v1 DBRP combinations to a database:

database_name/retention_policy_name

Database naming examples

Table and column limits

In {{< product-name >}}, table (measurement) and column limits can be configured using the --max-tables and --max-columns flags.

Table limit

Default maximum number of tables: 500

Each measurement is represented by a table in a database. Your database's table limit can be raised beyond the default limit of 500. InfluxData has production examples of clusters with 20,000+ active tables across multiple databases.

Increasing your table limit affects your {{% product-name omit=" Clustered" %}} cluster in the following ways:

{{< expand-wrapper >}} {{% expand "May improve query performance <em style='opacity:.5;font-weight:normal;'>View more info</em>" %}}

Schemas with many measurements that contain focused sets of tags and fields can make it easier for the query engine to identify what partitions contain the queried data, resulting in better query performance.

{{% /expand %}} {{% expand "More PUTs into object storage <em style='opacity:.5;font-weight:normal;'>View more info</em>" %}}

By default, {{< product-name >}} partitions data by measurement and time range and stores each partition as a Parquet file in your cluster's object store. By increasing the number of measurements (tables) you can store in your database, you also increase the potential for more PUT requests into your object store as InfluxDB creates more partitions. Each PUT request incurs a monetary cost and will increase the operating cost of your cluster.

{{% /expand %}} {{% expand "More work for the compactor <em style='opacity:.5;font-weight:normal;'>View more info</em>" %}}

To optimize storage over time, your {{< product-name omit=" Clustered" >}} cluster contains a compactor that routinely compacts Parquet files in object storage. With more tables and partitions to compact, the compactor may need to be scaled (either vertically or horizontally) to keep up with demand, adding to the operating cost of your cluster.

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Column limit

Default maximum number of columns: 250

Time, fields, and tags are each represented by a column in a table. Increasing your column limit affects your {{% product-name omit=" Clustered" %}} cluster in the following ways:

{{< expand-wrapper >}} {{% expand "May adversely affect query performance" %}}

At query time, the InfluxDB query engine identifies what table contains the queried data and then evaluates each row in the table to match the conditions of the query. The more columns that are in each row, the longer it takes to evaluate each row.

Through performance testing, InfluxData has identified 250 columns as the threshold beyond which query performance may be affected (depending on the shape of and data types in your schema).

{{% /expand %}} {{< /expand-wrapper >}}