Table DDL logs

The DDL log records every change the platform made to your tables, one run at a time: what changed, which statements ran, and what failed. It sits in the ClickHouse tab of Observability, next to the views described in ClickHouse activity.

Open the DDL log

Open Observability from the sidebar.
Click ClickHouse in the row of tabs at the top.
Click DDL log in the view toggle.

The DDL log appears in the toggle only if your role holds View Table DDLs. See Permissions below.

Read the run list

Each row is one run, and the list opens with the newest first. Use the search box, the column filters and Period to narrow it; Periods, filters and exports describes how these shared controls behave.

Column	What it shows
Started At	When the run started.
Status	`running`, `succeeded` or `failed`.
Kind	What the run did: `create`, `drop`, `alter`, `truncate`, `delete`, `insert`, `refresh`, `replace` or `sync`.
Database and Table	The database and the table the run changed.
Duration	How long the run took: milliseconds under a second, seconds under a minute, then minutes and seconds.
Error	The run's error, when it failed. The column is not sortable.
Finished At	When the run finished.
User	The user the run is recorded for.
Table ID	The table's identifier, shown as a number when present.
Run ID	The run's identifier.

Status and Kind are colour-toned badges: red for a failure and for destructive kinds such as drop, truncate and delete, green for a success, informational for in-progress states and for create and replace, and amber for alter.

Open a run

Click a row to open the run's details on the right; click the same row again to close them.
Read the header: the changed table's name, the run's status and kind, its duration, the number of statements the run holds and how many failed, and when the run started.
Read the notices above the statements: Run error when the run failed, and Recreation reasons when the platform recorded reasons for recreating the table.
Read the Statements list, described below.
Expand Schema changes, collapsed by default, to see the schema changes recorded for the run.

Read the statements

The Statements list is a timeline of what the run executed, in order. When the panel opens, the first failed statement is already expanded; if none failed, the first statement is.

Each row is labelled with the object the statement names, usually the table, and shows its duration with a small bar, relative to the run's longest statement.
Click a row to expand it. You then see the operation, the channel the statement used (Command, Command (no wait) or Bulk insert), its status as a word next to an icon (Succeeded, Failed or Submitted; an unrecognised value reads Submitted), and the statement's SQL.
SQL longer than 12 lines is clamped; use Show all N lines to expand it and Show less to clamp it again.
A failed statement shows a Statement error notice with the reason. When no SQL was recorded, the row reads No SQL was recorded for this statement.
Use Copy SQL to copy a statement's text; the check mark clears after two seconds.
Move between statements with the up and down arrow keys; Home and End jump to the first and last statement.

Export the log

Set Period, and filter or search as needed.
In the export control in the toolbar, pick CSV, Excel, JSON or TSV, then click the download icon next to it.

The export contains the rows that match your period, filters, sorting and search. The file is named after the log and the date, for example table_ddl_logs_2026-10-16.xlsx.
An export holds at most 300,000 rows. To get more, narrow the Period or add filters, and export in parts.
The export control shows only if your role holds Export Table DDLs. Reading the log and exporting it are separate permissions.

Periods and limits

Period offers Today, Last 7d, Last 30d and Custom, and starts on Last 7d. Your choice is remembered in this browser, not on your account.
A custom range can span at most one year. A longer range is refused with Date range too large and the message Custom date range cannot exceed 1 year. The Date and period pickers page covers the picker itself.
Rows per page starts at 50; you can pick 50, 100 or 200.
If the log cannot load at first, you see Failed to load table DDL logs with the reason. If a later load fails, the table keeps its rows and your search text, and an error bar with Retry appears above it. A failed refresh reads Refresh failed, and a failed export reads Export failed. See Observability troubleshooting for the full list of messages.

Permissions

To do this	You need
See the DDL log	View Table DDLs, preset Table DDL Viewer
Export the log	Export Table DDLs, preset Table DDL Manager

The Observability Administrator preset includes both. The Observability Viewer preset includes viewing the log but not exporting it. See Roles and permissions and the Permission reference.

Questions, answered

A Warehouse table was recreated. How do I find out why?

Open Observability > ClickHouse > DDL log, set Period to cover the change, and find the run for that table. Open the run. When the platform recorded reasons for the recreation, its Recreation reasons notice lists them.

Who changed a table?

Find the change in the DDL log and read its User column, which shows the user the run is recorded for. Open the run to see the statements it executed.

Why does the timeline show `CREATE TABLE` when the SQL says `CREATE OR REPLACE TABLE`?

The operation next to a statement collapses common modifiers, so CREATE OR REPLACE TABLE and CREATE TABLE IF NOT EXISTS both read CREATE TABLE. The recorded SQL itself is unchanged.

Why does a rename statement show the old table name?

The label takes the first table name the statement mentions. For a rename, that is the table being renamed; the new name appears on the line below.

Why is a statement's SQL cut off?

Long SQL is clamped at 12 lines so the panel stays readable. Use Show all N lines to expand it, and Show less to collapse it again.

A run is marked Failed. Where do I see the error?

Open the run. A Run error notice shows the run's error, and each failed statement carries a Statement error notice with its own reason. The Error column also shows the run's error in the list.

Why does a run show no statements?

The record for that run holds no statements, and the panel says so. When present, the Recreation reasons and Schema changes parts still describe the change.

What is in the Schema changes section?

The schema changes the run recorded, kept as structured JSON. It stays collapsed by default; expand it to read it.

Why can't I sort the Error column?

The Error column is not sortable. To find failures, filter Status to failed, or filter the Error column itself.

Why is the export button missing on the DDL log?

Exporting needs Export Table DDLs, which is separate from reading the log. Ask an administrator for the Table DDL Manager preset or the permission.

What is the difference between the DDL log and Query Management?

The DDL log follows the table changes the platform made and the statements inside each run. Query Management holds the queries themselves, including the platform's own queries. Use the DDL log for a table's history, and Query Management to find, reuse or investigate queries.

Why can't I see the DDL log?

The view needs View Table DDLs. It appears in the ClickHouse view toggle only if your role holds it; ask an administrator for the Table DDL Viewer preset or the permission.