In Redis, the SINTER command returns the members of the set resulting from the intersection of all the given sets.
DBMS
Database Management Systems
Subtract Seconds from a Time Value in PostgreSQL
In PostgreSQL, we can use the - operator to subtract one or more seconds from a time value.
By “time” value, this could be an actual time value, a timestamp, or an interval. We can also subtract seconds from a date value or a date and time combination.
Redis SDIFFSTORE Command Explained
In Redis, the SDIFFSTORE command works just like the SDIFF command, except that instead of returning the result, it stores it in the key that we specify. The destination key will then hold the members of the set resulting from the difference between the first set and all the successive sets.
5 Ways to See if a Table has a Generated Column in MySQL
MySQL supports generated columns. If you’re not sure whether a table has a generated column or not, you can check it using any of the following methods.
Redis SDIFF Command Explained
In Redis, the SDIFF command returns the members of the set resulting from the difference between the first set and all the successive sets. In other words, it returns all members of the first set that aren’t in any of the successive sets.
How to Return the Expiry Time as a Unix Timestamp in Redis
In Redis, we have several options for returning the expiry time of a key. One option from Redis 7.0.0 and above is to return it as a Unix timestamp.
When returning the expiry as a Unix timestamp, we can have it returned in seconds or milliseconds. To return it in seconds, we can use the EXPIRETIME command. To return it in milliseconds, we can use the PEXPIRETIME command.
2 Ways to Set a Redis Key Only When it Doesn’t Already Exist
In Redis, it’s possible to set a key only if it doesn’t already exist. As with most things, there’s more than one way to do this.