A problem few developers are aware of is the possibility of running into "cursor cache contention" or "execution plan cache contention" problems when using IN lists in SQL. The problem that is described in lengths in previous articles, can be summarised as this. All of these are distinct SQL queries and need to be parsed … Continue reading Use IN List Padding to Your JDBC Application to Avoid Cursor Cache Contention Problems
Hah! Got nerd-sniped again: https://stackoverflow.com/questions/43099226/how-to-make-jooq-to-use-arrays-in-the-in-clause/43102102 A jOOQ user was wondering why jOOQ would generate an IN list for a predicate like this: Java COLUMN.in(1, 2, 3, 4) SQL COLUMN in (?, ?, ?, ?) ... when in fact there could have been the following predicate being generated, instead: COLUMN = any(?::int) In the second case, … Continue reading SQL IN Predicate: With IN List or With Array? Which is Faster?
In their eternal attempts to circumvent the N+1 problem, Hibernate users often resort to IN predicates with ID lists. In this post, we'll see how those users might just be replacing a horrible thing with a bad one, which is better but not yet good. Here's why: The N+1 Problem The N+1 problem is a … Continue reading ID Lists Aren’t the Best Solution for the N+1 Problem