Scheduled Queries

Backfilling Mechanism

Running the queries for previous dates which the scheduled queries run may have got missed.

Example

Suppose having:

  • a source table that is refreshed daily
  • a scheduled query that runs every day that looks out the source table and based on the current date loads it to another table

If some day, source table is corrupted and not populated for the last 3 days. Suppose you have restored the last 3 days on source table.

Is last three days data in the another table gone? No

Backfill allows us to run the query within a pecified date range

Hou to use Backfill

Go to BigQuery > Scheduled queries > More (on top right of the page) > Schedule backfill. (see image)

Here:

  • start date is inclusive
  • end date is exclusive

Note: here the dates must be in UTC, but queries schedules in dashboard are in local timezone

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