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hash-data merged 5 commits into from
May 22, 2026
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docs: Update MSSQL doc with read only replica #424

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e5eb3db
update mssql with read only replica
nayanj98 May 21, 2026
0ef0ec4
added validation video requirement in contribution
nayanj98 May 21, 2026
b1002a4
updated read replica section based on tech review
nayanj98 May 21, 2026
0d84dfb
mentioned parameter to be added in UI
nayanj98 May 21, 2026
3b9b8cf
spelling corrected for sync
nayanj98 May 22, 2026
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2 changes: 1 addition & 1 deletion blog/2026-04-22-spark-vs-fusion-compaction.mdx
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Expand Up @@ -219,7 +219,7 @@ Fusion shows one additional resource because that node runs the Fusion service i

OLake Fusion takes a tiered compaction approach, giving you three levels of optimization that can be scheduled independently based on how aggressively you want to maintain your tables.

All three compaction tiers are explained there in detail, so definitely check out the [OLake Iceberg Maintenance docs](/docs/iceberg-maintenance/optimization/overview).
All three compaction tiers are explained there in detail, so definitely check out the [OLake Iceberg Maintenance docs](/docs/iceberg-maintenance/compaction/overview/).

For this benchmark, we used a **512 MB target file size**, so each tier behaves as follows:

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12 changes: 12 additions & 0 deletions docs/community/issues-and-prs.mdx
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Expand Up @@ -117,6 +117,18 @@ Next, take a pull (in case any new code has been added, this will help you avoid
- Describe how you tested your change.
- Check the Preview tab to make sure the Markdown is correctly rendered and that all tags and references are linked. If not, go back and edit the Markdown.

### 5. Attach a validation video

For every pull request, please record and attach a short video demo of your change. This helps reviewers quickly understand the behavior and verify that it works end-to-end with OLake, and also ensures contributors actually run OLake with their changes.

Your video should:

- Quickly walk through the relevant code changes.
- Execute a sync using OLake that exercises those changes.
- Highlight logs or UI views confirming that the run completes successfully.

**PRs without a validation video will not be reviewed!**

### Request Review
- Once your PR is ready, remove the "[WIP]" from the title and/or change it from a draft PR to a regular PR.
- If a specific reviewer is not assigned automatically, please request a review from the project maintainer.
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38 changes: 28 additions & 10 deletions docs/connectors/mssql/index.mdx
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Expand Up @@ -145,6 +145,23 @@ ALTER ROLE db_owner ADD MEMBER [username];
- **Columnstore indexes**: CDC cannot be enabled on tables with a clustered columnstore index. Starting with SQL Server 2016, it can be enabled on tables with a nonclustered columnstore index.
- **Computed columns**: CDC doesn't support values for computed columns, even if defined as persisted. Computed columns included in a capture instance will always have a value of `NULL`. This is intended behavior, not a bug.

#### 5. Using a Read-Only Secondary Replica
Comment thread
vishalm0509 marked this conversation as resolved.

To connect the MSSQL source to a read-only secondary replica, set the following JDBC URL parameter in the source configuration:

```json
"jdbc_url_params": {
"ApplicationIntent": "ReadOnly"
}
```

In **OLake UI**, add this under **JDBC URL Parameters** as a key-value pair: `ApplicationIntent` (key) and `ReadOnly` (value).

:::info
- CDC must be enabled on the primary database.
- If you enable **Manage Capture Instance** while connecting to a read-only secondary replica, OLake cannot create or drop CDC capture instances automatically because that requires write access on the primary database. In this mode, capture instances must be **created and maintained manually** on the primary database when using a secondary replica for sync.
:::

### Connection Prerequisites

- Read access to the tables for the MSSQL user.
Expand Down Expand Up @@ -185,7 +202,7 @@ ALTER ROLE db_owner ADD MEMBER [username];
| SSL Mode | SSL configuration for the database connection. Contains details such as the SSL mode. | `disable` |
| Retry Count | Number of times the retry will take place incase of timeout before failing the sync. | `3` |
| Manage Capture Instance | When enabled, it automatically creates and manages CDC capture instances on schema evolution. | `true/false` |

| JDBC URL Parameters | Extra [JDBC URL parameters](https://learn.microsoft.com/en-us/sql/connect/jdbc/setting-the-connection-properties?view=sql-server-ver17#properties) for fine-tuning the connection. | `{"connectTimeout":"20"}` |
### 3. Test Connection

- Once the connection is validated, the MSSQL source is created. Jobs can then be configured using this source.
Expand All @@ -208,15 +225,16 @@ An example `source.json` file will look like this:

| Field | Description | Example Value | Type |
| ----------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------- | ------ |
| MSSQL Host `required` | Hostname or IP address of the MSSQL database server. | `MSSQL-host` | String |
| MSSQL Port `required` | TCP port on which the MSSQL listener is accepting connections. | `1433` | Integer |
| Database Name `required` | The name of the target database to connect to. | `olake-db` | String |
| Password `required` | The password corresponding to the provided username for authentication. | `mssqlpwd` | String |
| Username `required` | Database user used to authenticate the connection. | `mssql-user` | String |
| Max Threads | Maximum number of worker threads the connector can spin up for parallel tasks. | `10` | Integer |
| SSL Mode | SSL configuration for the database connection. Contains details such as the SSL mode. | `disable` | Object |
| Retry Count | Number of times the retry will take place incase of timeout before failing the sync. | `3` | Integer |
| Manage Capture Instance | When enabled, it automatically creates and manages CDC capture instances on schema evolution. | `true/false` | Boolean |
| host `required` | Hostname or IP address of the MSSQL database server. | `MSSQL-host` | String |
| port `required` | TCP port on which the MSSQL listener is accepting connections. | `1433` | Integer |
| database `required` | The name of the target database to connect to. | `olake-db` | String |
| password `required` | The password corresponding to the provided username for authentication. | `mssqlpwd` | String |
| username `required` | Database user used to authenticate the connection. | `mssql-user` | String |
| max_threads | Maximum number of worker threads the connector can spin up for parallel tasks. | `10` | Integer |
| ssl | SSL configuration for the database connection. Contains details such as the SSL mode. | `disable` | Object |
| retry_count | Number of times the retry will take place incase of timeout before failing the sync. | `3` | Integer |
| manage_capture_instances | When enabled, it automatically creates and manages CDC capture instances on schema evolution. | `true/false` | Boolean |
| jdbc_url_params | Extra [JDBC URL parameters](https://learn.microsoft.com/en-us/sql/connect/jdbc/setting-the-connection-properties?view=sql-server-ver17#properties) for fine-tuning the connection. | `{"connectTimeout":"20"}` | Object |

Similarly, `destination.json` file can be created inside this folder. For more information, see destination documentation.

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