Add MariaDB setup docs for Database Monitoring

Adds dedicated Database Monitoring setup documentation for MariaDB
(self-hosted and RDS), advanced configuration, and troubleshooting
pages, plus the corresponding navigation menu entries and setup
partial.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: michaelperalta

config/_default/menus/main.en.yaml

@@ -4837,11 +4837,36 @@ menu:
       parent: dbm_setup_mysql
       identifier: dbm_troubleshooting_mysql
       weight: 407
+    - name: Setting Up MariaDB
+      url: database_monitoring/setup_mariadb/
+      parent: dbm
+      identifier: dbm_setup_mariadb
+      weight: 6
+    - name: Self-hosted
+      url: database_monitoring/setup_mariadb/selfhosted
+      parent: dbm_setup_mariadb
+      identifier: dbm_setup_mariadb_selfhosted
+      weight: 451
+    - name: RDS
+      url: database_monitoring/setup_mariadb/rds
+      parent: dbm_setup_mariadb
+      identifier: dbm_setup_mariadb_rds
+      weight: 452
+    - name: Advanced Configuration
+      url: database_monitoring/setup_mariadb/advanced_configuration
+      parent: dbm_setup_mariadb
+      identifier: dbm_mariadb_advanced_configuration
+      weight: 453
+    - name: Troubleshooting
+      url: database_monitoring/setup_mariadb/troubleshooting/
+      parent: dbm_setup_mariadb
+      identifier: dbm_troubleshooting_mariadb
+      weight: 454
     - name: Setting Up SQL Server
       url: database_monitoring/setup_sql_server/
       parent: dbm
       identifier: dbm_setup_sql_server
-      weight: 6
+      weight: 7
     - name: Self-hosted
       url: database_monitoring/setup_sql_server/selfhosted/
       parent: dbm_setup_sql_server
@@ -4871,7 +4896,7 @@ menu:
       url: database_monitoring/setup_oracle/
       parent: dbm
       identifier: dbm_setup_oracle
-      weight: 7
+      weight: 8
     - name: Self-hosted
       url: database_monitoring/setup_oracle/selfhosted/
       parent: dbm_setup_oracle
@@ -4906,7 +4931,7 @@ menu:
       url: database_monitoring/setup_mongodb/
       parent: dbm
       identifier: dbm_setup_mongodb
-      weight: 8
+      weight: 9
     - name: Self-hosted
       url: database_monitoring/setup_mongodb/selfhosted
       parent: dbm_setup_mongodb
@@ -4926,7 +4951,7 @@ menu:
       url: database_monitoring/setup_clickhouse/
       parent: dbm
       identifier: dbm_setup_clickhouse
-      weight: 9
+      weight: 10
     - name: Self-hosted
       url: database_monitoring/setup_clickhouse/selfhosted
       parent: dbm_setup_clickhouse
@@ -4941,7 +4966,7 @@ menu:
       url: database_monitoring/setup_documentdb/
       parent: dbm
       identifier: dbm_setup_documentdb
-      weight: 8
+      weight: 11
     - name: Amazon DocumentDB
       url: database_monitoring/setup_documentdb/amazon_documentdb
       parent: dbm_setup_documentdb
@@ -4956,17 +4981,17 @@ menu:
       url: database_monitoring/connect_dbm_and_apm/
       parent: dbm
       identifier: dbm_connect_dbm_and_apm
-      weight: 10
+      weight: 12
     - name: Data Collected
       url: database_monitoring/data_collected
       parent: dbm
       identifier: dbm_data_collected
-      weight: 10
+      weight: 13
     - name: Collecting Custom Metrics
       url: database_monitoring/custom_metrics/
       parent: dbm
       identifier: dbm_custom_metrics
-      weight: 11
+      weight: 14
     - name: Exploring Custom Metrics
       url: database_monitoring/custom_metrics/exploring_custom_metrics
       parent: dbm_custom_metrics
@@ -4976,42 +5001,42 @@ menu:
       url: database_monitoring/database_hosts/
       parent: dbm
       identifier: dbm_database_hosts
-      weight: 12
+      weight: 15
     - name: Exploring Query Metrics
       url: database_monitoring/query_metrics/
       parent: dbm
       identifier: dbm_query_metrics
-      weight: 13
+      weight: 16
     - name: Exploring Query Samples
       url: database_monitoring/query_samples/
       parent: dbm
       identifier: dbm_query_samples
-      weight: 14
+      weight: 17
     - name: Exploring Database Schemas
       url: database_monitoring/schema_explorer
       parent: dbm
       identifier: dbm_schema_explorer
-      weight: 15
+      weight: 18
     - name: Exploring Recommendations
       url: database_monitoring/recommendations/
       parent: dbm
       identifier: dbm_recommendations
-      weight: 16
+      weight: 19
     - name: Database Investigator
       url: database_monitoring/database_investigator/
       parent: dbm
       identifier: dbm_database_investigator
-      weight: 17
+      weight: 20
     - name: Troubleshooting
       url: database_monitoring/troubleshooting/
       parent: dbm
       identifier: dbm_troubleshooting
-      weight: 18
+      weight: 21
     - name: Guides
       url: database_monitoring/guide/
       parent: dbm
       identifier: dbm_guides
-      weight: 19
+      weight: 22
     - name: Data Streams Monitoring
       url: data_streams/
       pre: datastreams-monitoring

content/en/database_monitoring/setup_mariadb/_index.md

@@ -0,0 +1,20 @@
+---
+title: Setting up MariaDB
+description: Setting up Database Monitoring on a MariaDB database
+disable_sidebar: true
+---
+
+### MariaDB versions supported
+
+|  | Self-hosted | Amazon RDS |
+|--|------------|---------|
+| MariaDB 10.5  | {{< X >}} | {{< X >}} |
+| MariaDB 10.6  | {{< X >}} | {{< X >}} |
+| MariaDB 10.11 | {{< X >}} | {{< X >}} |
+| MariaDB 11.4  | {{< X >}} |  |
+
+For setup instructions, select your hosting type:
+
+{{< partial name="dbm/dbm-setup-mariadb" >}}
+
+<br>

content/en/database_monitoring/setup_mariadb/advanced_configuration.md

@@ -0,0 +1,64 @@
+---
+title: Advanced Configuration for MariaDB Database Monitoring
+description: Advanced Configuration for MariaDB Database Monitoring
+
+---
+
+## Truncating `events_statements_summary_by_digest`
+
+Certain workloads require some maintenance on tables in `performance_schema`. Query statistics are aggregated in the `performance_schema.events_statements_summary_by_digest` table, which has a limit on the number of rows. This limit is specified by the [`performance_schema_digests_size` system variable][1]. If the table is full, new query digests are tracked in a catch-all row with null schema and null query digest, preventing the Agent from distinguishing between queries that make up that row.
+
+To prevent this loss of accurate per-query metrics, periodically truncate this table as a maintenance step so that all new queries can be collected:
+
+```sql
+TRUNCATE performance_schema.events_statements_summary_by_digest;
+```
+
+To determine the frequency of truncation, run the query below to determine the number of statements sent to this catch-all row per second. A value greater than zero means the table is full and should be truncated.
+
+```sql
+SHOW STATUS LIKE 'Performance_schema_digest_lost';
+```
+
+## Handling many identical tables
+
+Partitioning your database across tables, such that table definitions are identical except for the name, can result in a large number or normalized queries:
+
+```sql
+SELECT * FROM daily_aggregates_001
+SELECT * FROM daily_aggregates_002
+SELECT * FROM daily_aggregates_003
+```
+
+In these cases, track these queries as a single normalized query using the `replace_digits` option, so all metrics for those queries are rolled up into a single query:
+
+```sql
+SELECT * FROM daily_aggregates_?
+```
+
+Add the `replace_digits` option to your database instance configuration in the Datadog Agent:
+
+```yaml
+init_config:
+
+instances:
+  - dbm: true
+    ...
+    replace_digits: true
+```
+
+## Raising the sampling rate
+
+If you have queries that are relatively infrequent or execute fast, raise the sampling rate by lowering the `collection_interval` value to collect samples more frequently.
+
+Set the `collection_interval` in your database instance configuration of the Datadog Agent. The default value is 1. Lower the value to a smaller interval:
+
+```yaml
+instances:
+  - dbm: true
+    ...
+    query_samples:
+        collection_interval: 0.1
+```
+
+[1]: https://mariadb.com/kb/en/performance-schema-performance_schema_digests_size/