In Redis, the ZREMRANGEBYLEX command enables us to use a lexicographical range to remove members from a sorted set. That is, we can specify that all members between a given lexicographical range are removed.
This relies on all members having the same score (which forces lexicographical ordering).
Continue readingIn Redis, the ZREM command removes one or more members from the specified sorted set.
When creating a sequence object in SQL Server, it’s common to set various properties such as the start value, the increment, and even things like the maximum and minimum values for the sequence. But it is also possible to create a sequence without setting any of these properties.
Continue readingIf you get an error that reads “WRONGTYPE Operation against a key holding the wrong kind of value” when using the ZUNION or ZUNIONSTORE commands in Redis, it’s because you’re passing a key with the wrong data type.
To fix this issue, make sure the keys you pass to these commands contain either sets or sorted sets. Although these commands are for sorted sets, they also work with non-sorted sets.
Continue readingIn Redis, the ZINCRBY command increments the score of a given member in a sorted set.
Starting with Redis 6.2.0, the ZRANGE command added the REV, BYSCORE, BYLEX and LIMIT options. The addition of the first three means that the ZRANGE command can now do what the ZREVRANGE, ZRANGEBYSCORE, ZREVRANGEBYSCORE, ZRANGEBYLEX and ZREVRANGEBYLEX commands can do.
As a result, those commands are now deprecated (as of Redis 6.2.0).
Therefore, we should no longer use the ZREVRANGE command when we need to return a sorted set in descending order. Instead, we should use the ZRANGE command with the REV argument.
PostgreSQL provides us with several options when it comes to cloning a table. Below are six methods we can use to clone a table in Postgres. The method we use will depend on things like, whether or not we want to transfer the data, indexes, etc.
Continue readingIn Redis, the BZPOPMAX command is the blocking variant of the ZPOPMAX command.
The BZPOPMAX command works similar to ZPOPMAX when any of the sorted sets contain elements. That is, it pops a member with the highest score from the sorted set.
In Redis, the BZPOPMIN command is the blocking variant of the ZPOPMIN command.
The BZPOPMIN command works similar to ZPOPMIN when any of the sorted sets contain elements. That is, it pops a member with the lowest score from the sorted set.
In Redis, the ZMPOPMAX command removes and returns (pops) members with the highest scores from the specified sorted set. By default it pops one member, but we can also specify how many members we want to pop.