The Redis PEXPIRE command sets a timeout on a given key in milliseconds. After the timeout has expired, the key will be deleted.
The PEXPIRE command works exactly the same as the EXPIRE command, except that it returns the timeout in milliseconds instead of seconds.
The Redis EXPIRE command sets a timeout on a given key in seconds. After the timeout has expired, the key will be deleted.
Redis also has a PEXPIRE command that works the same as EXPIRE, except that it returns the timeout in milliseconds instead of seconds.
A key with a timeout is said to be volatile in Redis terminology.
Continue readingMost RDBMSs provide at least a few ways to return rows that contain uppercase characters. Here are some options available in the major RDBMSs.
Continue readingIn Redis, the STRLEN command returns the length of the string stored at a given key.
The Redis PSETEX command sets a key to hold a given string value, and sets that key to time out after a given number of milliseconds.
In Redis, the SETEX command sets a key to hold a given string value, and sets that key to time out after a given number of seconds.
In Redis, the APPEND command appends a given value to the end of the value of a specified key.
If the key doesn’t exist, APPEND creates the key with the empty string and appends the value to it (so it basically works like the SET command in this case).
Here’s an example of returning the first day of a given month in Oracle Database. We can return the first day of the current month, a previous or later month, or the first day of a month based on a specified date.
Continue readingThe Redis GETDEL command gets the value of a given key, then deletes that key. It’s similar to the GET command, except that it deletes the key on success (the GET command doesn’t delete the key – it only returns its value).
An error is returned if the value stored at key is not a string.
The GETDEL command was introduced in Redis 6.2.0.
In Redis, the DEL command removes one or more keys. If a specified key doesn’t exist, it’s ignored.