Dear all, I'm running a query from Java on a postgres database:
Java version: 17 JDBC version: 42.4.2 Postgres version: 13.1 In parallel I'm testing the same queries from pgAdmin 4 version 6.13 The tables I'm using contains more than 10million rows each and I have two questions here: 1. I need to extract the path of a file without the file itself. For this I use two alternatives as I found that sentence "A" is much faster than the "B" one: "A" sentence: SELECT DISTINCT ( LEFT(opf.file_path, length(opf.file_path) - position('/' in reverse(opf.file_path))) ) AS path FROM product AS op JOIN product_file AS opf ON opf.product_id = op.id WHERE op.proprietary_end_date <= CURRENT_DATE AND op.id LIKE 'urn:esa:psa:%' "B" sentence: SELECT DISTINCT ( regexp_replace(opf.file_path, '(.*)\/(.*)$', '\1') ) AS path FROM product AS op JOIN product_file AS opf ON opf.product_id = op.id WHERE op.proprietary_end_date <= CURRENT_DATE AND op.id LIKE 'urn:esa:psa:%' 2. Running sentence "A" on the pgAdmin client takes 4-5 minutes to finish but running it from a Java program it never ends. This is still the case when I limit the output to the first 100 rows so I assume this is not a problem with the amount of data being transferred but the way postgres resolve the query. To make it work in Java I had to define a postgres function that I call from the Java code instead of running the query directly. I had a similar problem in the past with a query that performed very poorly from a Java client while it was fine from pgAdmin or a python script. In that case it was a matter of column types not compatible with the JDBC (citext) deriving in an implicit cast that prevented the postgres engine from using a given index or to cast all the values of that column before using it, not sure now. But I don't think this is not the case here. Could anyone help me again? Many thanks in advance Jose