Write Database for large dataset

robin
robin New Altair Community Member
edited November 2024 in Community Q&A

I am attempting to limit the number of queires supplied back from the Read Database operator. When I write the code in SQL the LIMIT operator does not seem to be valid. What should I be using? 

SELECT `id_unique`
FROM `retrieved_id`
WHERE `id_count` IS NOT NULL
LIMIT 1000

Rapid Miner is giving me the full database back instead of the first 1k rows. 

Best Answer

  • BalazsBaranyRM
    BalazsBaranyRM New Altair Community Member
    Answer ✓

    Hi,

     

    which database system are you using? 

     

    For me it works with PostgreSQL and MySQL, just tested with different limits (1000, 1300, 1500 etc.)

     

    The query is interpreted by your database server. RapidMiner just sends it to the database. (If "prepare statement" is checked, a bit differently, you could play with that.)

     

    Could you test the same query in some other tool (SQL client like SQuirrel SQL) with the same database?

     

    Regards,

    Balázs

     

Answers

  • BalazsBaranyRM
    BalazsBaranyRM New Altair Community Member
    Answer ✓

    Hi,

     

    which database system are you using? 

     

    For me it works with PostgreSQL and MySQL, just tested with different limits (1000, 1300, 1500 etc.)

     

    The query is interpreted by your database server. RapidMiner just sends it to the database. (If "prepare statement" is checked, a bit differently, you could play with that.)

     

    Could you test the same query in some other tool (SQL client like SQuirrel SQL) with the same database?

     

    Regards,

    Balázs

     

  • robin
    robin New Altair Community Member

    For some reason it now likes me and is working as designed.