Merge pull request #87 from Altinity/clickhouse_timezone_settings

Clickhouse timezone settings

Author: subkanthi

examples/docker-compose/README.md

@@ -28,7 +28,41 @@ Solution: Upgrade docker/docker compose to v2.
 
 ### Supplemental
 
+#### Setting ClickHouse Server Timezone
+
+To configure the ClickHouse server timezone:
+
+1. Edit `config.xml` with your desired timezone:
+
+```xml
+<clickhouse replace="true">
+    <timezone>America/Chicago</timezone>
+</clickhouse>
+```
+
+2. Uncomment the volume mount in `docker-compose.yaml` under the `clickhouse` service:
+
+```yaml
+volumes:
+  - ./config.xml:/etc/clickhouse-server/conf.d/config.xml
+```
+
+3. Restart the containers: `docker compose down && docker compose up`
+
 #### Querying data using Spark
+To set the session timezone in spark, uncomment and set the value for the variable `spark.sql.session.timeZone` 
+under the section.
+```
+configs:
+  spark-defaults.conf:
+    content: |
+```
+
+```
+ # spark.sql.session.timeZone                America/Chicago
+```
+
+This ensures that Spark SQL sessions will use the specified timezone.
 
 ```shell
 docker compose -f docker-compose-spark-iceberg.yaml down -v

examples/docker-compose/config.xml

@@ -0,0 +1,3 @@
+<clickhouse replace="true">
+    <timezone>America/Chicago</timezone>
+</clickhouse>

examples/docker-compose/docker-compose-spark-iceberg.yaml

@@ -33,4 +33,5 @@ configs:
       spark.eventLog.dir                        /home/iceberg/spark-events
       spark.history.fs.logDirectory             /home/iceberg/spark-events
       spark.sql.catalogImplementation           in-memory
+      # spark.sql.session.timeZone                America/Chicago
       # spark.log.level                         DEBUG

examples/docker-compose/docker-compose.yaml

@@ -40,7 +40,7 @@ services:
     depends_on:
       - minio-init
   clickhouse:
-    image: altinity/clickhouse-server:25.3.3.20186.altinityantalya-alpine
+    image: altinity/clickhouse-server:25.8.9.20496.altinityantalya-alpine
     restart: unless-stopped
     environment:
       CLICKHOUSE_SKIP_USER_SETUP: "1" # insecure
@@ -53,6 +53,7 @@ services:
     volumes:
       # for access to clickhouse-logs
       - ./data/docker-compose/clickhouse/var/log/clickhouse-server:/var/log/clickhouse-server
+      # - ./config.xml:/etc/clickhouse-server/conf.d/config.xml
     depends_on:
       - ice-rest-catalog
 configs: