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I struggle to understand why the Halloween Problem is listed as a Postgres issue. The concept that a where condition would run until all rows are condition fals
by upon_drumhead 3y ago
I struggle to understand why the Halloween Problem is listed as a Postgres issue. The concept that a where condition would run until all rows are condition false is just categorically false for Postgresql.
https://en.wikipedia.org/wiki/Halloween_Problem https://en.wikipedia.org/wiki/Halloween_Problem
- smitty1e 3y agoThe Famous Article points out that the meme is generally applicable to any RDBMS, but was being explored in a PostGreSql context.
- upon_drumhead 3y agoYes, and they call it out as a concern, which it isn't with Postgresql. > This could even cause an infinite loop in some cases where updates continually place the updated record ahead of the scan performing the update operation. This just is not true for Postgresql and they don't specify anywhere that they switched from talking about Postgresql to a different database. So either they believe it's an concern with Postgresql or they aren't being clear when they are talking about different databases.
- MrPowerGamerBR 3y agoThey didn't call it out as a concern, they said at the beginning of the section "Halloween Problem is a database error that a database system developer needs to be aware of." To be honest, just like you I also thought that it was related to PostgreSQL or other popular SQL databases somehow, until I re-read the section multiple times.
- smitty1e 3y agoI was pointing to the article as a whole, not just the Halloween Problem section, and regret if I read too quickly.
- pmcjones 3y agoNo, it was being explored in the context of System R at IBM San Jose Research -- see this link in the Wikipedia article: http://www.mcjones.org/System_R/SQL_Reunion_95/sqlr95-System.html http://www.mcjones.org/System_R/SQL_Reunion_95/sqlr95-System...
- deleted 3y ago[deleted]