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Reconstructing a Missing Table Incident from Metadata and Delta History
I was working on a routine data review when I noticed that the orders table in the production.sales database was missing. This was unexpected because the table had been a critical part of our sales analytics. I wanted to understand what had happened and how to recover the data. I started by checking what tables were present in the production.sales database.
SHOW TABLES IN production.sales;
| database | tableName | isTemporary |
|---|---|---|
| sales | customers | false |
| sales | orders | false |
I noticed that the orders table was still listed, but I wasn’t sure if it was the same one that had gone missing. To confirm, I decided to look at the extended table description to understand its structure and any associated metadata.
DESCRIBE TABLE EXTENDED production.sales.orders;
| col_name | data_type | comment |
|---|---|---|
| order_id | bigint | order identifier |
| customer_id | bigint | customer identifier |
| region | string | sales region |
| amount | decimal(12,2) | order amount |
| status | string | order status |
The table structure looked familiar, but I needed more information to determine if there had been any changes or deletions. I decided to check the Delta history for the orders table. This would show me the version history and any operations that had been performed on the table.
DESCRIBE HISTORY production.sales.orders;
| version | timestamp | userName | operation |
|---|---|---|---|
| 12 | 2026-09-11 14:32:10 | analyst@demo.com | WRITE |
| 11 | 2026-09-11 13:18:42 | engineer@demo.com | MERGE |
| 10 | 2026-09-11 09:05:17 | admin@demo.com | CREATE TABLE |
Looking at the history, I noticed that the latest operation was a WRITE by analyst@demo.com at 14:32. This suggested that the table had been actively used recently. However, the fact that the table was still present in the list but missing from the data made me wonder if there had been an accidental deletion or a data loss event.
I verified the latest version of the table by checking the latest version number and the associated timestamp. The WRITE operation at 14:32 was the most recent, indicating that the table was still present in the system, but something might have gone wrong with the data itself.
With this information, I was able to trace the table’s history and understand that the data might have been deleted or overwritten. I could now proceed to investigate further by examining the data at each version or by restoring a previous state if needed.
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