The library is available on Maven Central, so you can get it via the following dependency:įrom the Tsid object, we can extract the following values: The node identifier can also be provided via the TSIDCREATOR_NODE environment variable: The node identifier can be provided by the tsidcreator.node system property when bootstrapping the application: One such implementation is offered by the Hypersistence TSID OSS library, which provides a 64-bit TSID that’s made of two parts: If you plan to store UUID values in a Primary Key column, then you are better off using a TSID (time-sorted unique identifier). UUID or GUID as Primary Keys? Be Careful!.Percona: UUIDs are Popular, but Bad for Performance.In fact, almost any database expert will tell you to avoid using the standard UUIDs as database table Primary Keys: If you’re using SQL Server or MySQL, then it’s even worse because the entire table is basically a clustered index.Īnd all these problems will affect the secondary indexes as well because they store the Primary Key value in the secondary index leaf nodes. Because the B+Tree index needs to rebalance itself in order to maintain its equidistant tree structure, the random key values will cause more index page splits and merges as there is no pre-determined order of filling the tree structure.So, a page of 8kB will end up storing just a few elements, therefore wasting a lot of space, both on the disk and in the database memory, as index pages could be cached in the Buffer Pool. Index pages will have a very low fill factor because the values come randomly.However, indexing random values using B+Tree causes a lot of problems: Second, the Primary Key column usually has an associated B+Tree index to speed up lookups or joins, and B+Tree indexes store data in sorted order. Every single record will need 16 bytes for the database identifier, and this impacts all associated Foreign Key columns as well. ![]() ![]()
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