CODEWITHSUNDEEP
sqldatabasepostgresql
Siva
Siva

Reputation: 1276

How wide can a postgresSQL table be before I run into issues?

According to the limits postgres supports up to 1600 columns per table. https://www.postgresql.org/docs/current/limits.html

I understand that it's bad practice to have so many columns but what are the consequences of approaching this limit?

For example, will a table with 200 columns perform fine in an application? How can you tell when you're approaching too many columns for a given table?

Upvotes: 0

Views: 219

Answers (1)

Laurenz Albe
Laurenz Albe

Reputation: 246523

The hard limit is that a table row has to fit inside a single 8kB block.

The "soft limits" you encounter with many columns are

  • writing SELECT list becomes more and more annoying (never, ever, use SELECT *)

  • each UPDATE has to write a large row version, so lots of data churn

  • extracting the 603th column from a row requires skipping the previous 602 columns, which is a performance hit

  • it is plain annoying if the output of \d is 50 pages long

Upvotes: 1

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