Fixing a hang when upserting 90,000 rows with :batchexec

[austincollinpena]

Maybe this will help someone in the future!

I dealt with a situation, of unknown cause, where a :batchexec would cause the program to stall. I don't know why it would happen, but I found a fix.

I chunked the bulk insert arguments (https://stackoverflow.com/a/72408490) and ran them concurrently inside of an errGroup.

Fixing the root cause is better but this works for now!

	chunks := chunkBy[db_access.AdGroupPerformanceUpdateParams](p, 1000)
	errGroup, ctx := errgroup.WithContext(ctx)
	errGroup.SetLimit(maxConcurrency)
	for _, chunk := range chunks {
		chunkCopy := chunk
		errGroup.Go(func() error {
			batch := q.AdGroupPerformanceUpdate(ctx, chunkCopy)
			var outsideErr error
			batch.Exec(func(i int, err error) {
				if err != nil {
					outsideErr = err
					batch.Close()
				}
			})
			return outsideErr
		})
	}