I have a problem creating a usable index for the following simple query: SELECT * FROM my.table WHERE node = '10' ORDER BY id DESC LIMIT 1
id is a serial, so the query is to find the latest entry to a given node and id is the primary key. The table contains around 1 million records and the query takes around 2 seconds.
I have tried to make an index on node and also on both id & node, but is doesn't lower the
query time. What am I doing wrong ? Thanks, Poul ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match