Creating or updating a table from a select statement in Google BigQuery

By using scripting with a variable to optimize data processing for a query Google BigQuery optimization with subquery in WHERE clause, the ability to specify a destination was lost.

Modeling a solution described in an answer to the question Get a Big Query script to output a table, generates a 'configuration.query.writeDisposition cannot be set for scripts' error.

What are options to address the error, where the data are needed to be written (overwritten) to a table? This is necessary to allow for post-processing and writing (appending) to another table for reporting.

The script is given below.

DECLARE start_date STRING;
SET start_date = (SELECT MAX(date) FROM `my-project-12345.dataset.my-data-table`);
CREATE OR REPLACE TABLE `my-project-12345.dataset.my-staging-table`
AS SELECT
  GA.date, 
  GA.field1, 
  hits.field2, 
  hits.field3
FROM 
  `my-project-12345.dataset.ga_sessions_*` AS GA, UNNEST(GA.hits) AS hits
WHERE 
  hits.type IN ('PAGE', 'EVENT')
  AND hits.field0 = 'some value'
  AND _TABLE_SUFFIX > start_date
  AND _TABLE_SUFFIX < '20201025'