Tag Archives: Redshift

Some tips about BigQuery on GCP

Migrate SQL script from AWS Redshift to BigQuery

in Redshift should be changed to

in BigQuery. Since BigQuery doesn’t force type conversion, some NULL value in Redshift could be a NULL value or a ‘NULL’ string in BigQuery. Make sure you use both

and

for checking…. Read more »

Use `psql` to download data as CSV file

Although SQL WorkBench is a handy tool for querying AWS Redshift, we still need to CLI tool for automation. To install psql on MacOS, we need to

Then we could download data without using \copy but only –csv

Processing date and time in AWS Redshift

Since AWS Redshift don’t have function like FROM_UNIX(), it’s much more weird to get formatted time from a UNIX timestamp (called ‘epoch’ in Reshift):

Ref: https://stackoverflow.com/questions/39815425/how-to-convert-epoch-to-datetime-redshift If we want to see the statistics result group by hours:

Some tips about “Amazon Redshift Database Developer Guide”

Show diststyle of tables

Details about distribution styles: http://docs.aws.amazon.com/redshift/latest/dg/viewing-distribution-styles.html How to COPY multiple files into Redshift from S3 http://docs.aws.amazon.com/redshift/latest/dg/t_loading-tables-from-s3.html Could “Group” (or “Order”) by number, not column name

COPY with automatical compression To apply automatic compression to an empty table, regardless of its current compression encodings, run the… Read more »