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Optimize Your Search with Partitions

What is a Partition?

A partition stores your data in an index separate from the rest of your account's data so you can optimize searches, manage variable retention, and specify certain data to forward to S3.

Partitions route your data to an index becoming a separate subset of data in your account. Creating smaller and separate subsets of data is central to search optimization. When you run a search against an index, results are returned more quickly and efficiently because the search runs against a smaller data set.

This example shows a customer that created three additional Partitions to separate data by environment.


Consider the following queries:

QueryPartition StatusPath
Query 1 _sourceCategory=prod/security/snort
Query 2Partitions in place_index=prod AND _sourceCategory=prod/security/snort
Query 3Partitions in place_sourceCategory=prod/security/snort
Query 4Partitions in place_sourceCategory=stage/aws/cloudtrail OR _sourceCategory=prod/security/snort
  • Query 1. There are no custom Partitions created and you only have the Default Index, 100% of your data across all partitions is scanned in order to find all production log messages for the Snort security app.
  • Query 2. Partitions do exist, _index=prod limits the scope of the query and only about 40% of the data is scanned to get the same results as Query 1. But it is redundant.
  • Query 3. You can take advantage of Partitions without having to rewrite your existing queries. Sumo Logic's behind-the-scenes Query Rewriting, performed for queries run against data, is smart enough to understand that the scope of what you are looking for is included within _index=prod; therefore at runtime, it will rewrite the query as Query 2.
  • Query 4. We want to search for data that is in a custom Partition, as well as data that exists in the Default Index. However, query rewriting does not have the ability to OR indexes together. Instead, another behind-the-scenes feature, Inverse View Rewriting kicks in, we know that the data is NOT contained in the DEV and QA index, so those will be skipped.  This query will only scan the Prod index and the Default Index.

What is Query Rewriting?

Whenever possible, we rewrite a user's queries to perform better. We'll illustrate this using a simple example below:.

This means that:


Will be rewritten as:

_index=prod AND _sourceCategory=prod/security/snort

This is possible because:

  • The example environment is using a robust _sourceCategory naming convention
  • The Partition was scoped using _sourceCategory
  • The searches are using _sourceCategory, so they can easily be mapped to Partitions
  • The scope of this search (_sourceCategory=prod/security/snort) falls within the scope of the Partition (_sourceCategory=prod/*)

Therefore, defining a broad scope for your Partitions (for example, _sourceCategory=prod/*), and searching with _sourceCategory allows you to take advantage of query rewriting, and it allows you to potentially not have to manually rewrite your existing queries.


We have used a simple example of non-overlapping partitions all defined on _sourceCategory. Your data organization needs may be more complex, and in those cases we try to do a best effort query re-writing.

Create a Partition

As an Admin, you create Partitions by specifying their routing expression. We recommend you use _sourceCategory to define your routing expressions to take full advantage of Query Rewriting.

The following example shows the routing expression for the three custom Partitions:


Here are simple steps to create a Partition named Dev:

  1. In the main Sumo Logic menu, select Manage Data > Logs > Partitions.
  2. Click Add Partition.
  3. In the Name field, enter Dev.
  4. In the Routing Expression field enter _sourceCategory=Dev.
  5. Select Apply the retention period of sumologic_default.
  6. Click Save.

How can my team use Partitions?

Once created, Partitions can be used by anyone in your account, helping you reduce the scope of your searches and improve the performance for all users. Query 2 above takes advantage of our newly created Partition to scan only 40% of the data. As noted above, Query 3 is also a good option, because Query Rewriting will produce the same results as Query 1. This might eliminate the need to edit all your queries once your Partitions are in place.

reduce scope

Best Practices when using Partitions

Avoid creating too many partitions to avoid fragmentation

We recommend 20 as the maximum number of partitions. This is to avoid both index fragmentation and data management issues.

Optimal partitions are sized between 1% and 30% of total ingest

Partitions that are too small may cause index fragmentation and degraded search performance. It is possible to create partitions larger than 30% without adverse effects, however the performance gains will be diminished.

Don’t create overlapping partitions

This will lead to duplication of data (increasing your billed ingest rate), and degraded performance. Sumo Logic will not return duplicate results, but the process of de-duplication is time consuming and will increase query durations.

Do not use the NOT operator in partition definitions

This will likely exclude data that should be contained within your partition and will reduce the chances that your partition will be reused by queries that are rewritten.

Do not use sourceHost to define your partitions

It may prevent you from searching horizontally without OR’ing partitions together.

Use an intuitive naming scheme

This helps users easily identify the correct partition to use.

Keep your partition broadly scoped with sourceCategory and avoid keywords

Use sourceCategory in your partitions definitions and avoid keywords to keep your partition broadly scoped. You can always narrow down the scope of your search when you query your partition.

Group similar data together

In the example above, we used prod/QA/Dev environment, as you will most often be searching across all your Prod data. If you need to search across environments, you can OR 2 or more Partitions.

More information

See Manage Partitions.

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