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ran into the json vs jsonb tradeoff on an old logging project, kept raw payloads in json to preserve spacing then copied searchable fields to jsonb for gin indexing. anyone still bother with plain json these days?
I dropped plain json entirely. I liked the decomposed binary storage because GIN queries and containment operators just work.
Same here. Dropped plain json years ago. Binary storage means containment operators and GIN actually perform, while plain json re-parses text every time. Same logic as picking bigint over integer by default. Storage is cheap, rewrites are not.
The extensibility pitch always sounds nice until you inherit five databases with five different money, email, status enums. Portability dies fast. Standards beat clever custom types.
CREATE TYPE status_mine AS ENUM ('ok');
> "Portability dies fast."
Portability only matters if you plan to leave. Most Postgres deployments never migrate to another engine, they migrate between Postgres installs. Custom types are opt-in. Nobody forces CREATE TYPE status_mine on you, but having the ability to model a domain correctly with an enum or composite instead of stuffing everything into varchar and validating it in app code is genuine leverage. Teams that abuse it would also make a mess with plain text columns.
The cost is discipline in code review, not the feature itself.
Exactly. Domain types also make constraints portable inside the database itself across schema dumps, so a fresh install gets the same validation without relying on every app. Have you ever checked how much varchar email validation disappears when you use citext or a proper inet column for addresses? That shared definition is the leverage standard types alone don't give.
Opt-in is exactly how it works, right up until the prod dump lands on your desk at 2am while the author is on holiday. Discipline in review is just hope with a checklist.
This reads like the classic Postgres docs page I've had bookmarked for years.
I was seeding a Postgres DB last month for a side project with about 10k test rows and needed quick UUIDs for the primary keys. I ended up using a simple UUID generator to bulk create v4s and paste them directly into the inserts. Handy to have this reference alongside that workflow.
For v7 ordering skip the external generator, PG18 has uuidv7() built in and it sorts by creation time natively for primary keys.
mysql types docs are clearer than this
Yeah MySQL lays out int display widths and auto_increment more plainly. Postgres buries the lede that smallserial serial and bigserial are just shorthand for integer with a sequence, not true types. Migrating later means altering sequences and defaults by hand, and dump/restore surprises people every time!
Disagree, MySQL's docs gloss over unsigned vs signed mess while Postgres at least admits input/output quirks. But smallint/bigint clarity is overstated for newcomers, isn't the serial mess proof? Good coverage, confusing naming.
Range and multirange types finally make booking availability logic manageable without hand-rolled overlap checks everywhere. Exclusion constraints actually work, intersections are readable, and I stop writing awful date arithmetic for every reservation system. Most codebases still ignore them and pay for it later. That is on them.
Timestamp round-trips still lose microseconds somewhere, apparently.
> Timestamp round-trips still lose microseconds somewhere, apparently.
That loss is usually client parsing or an intermediate format, not the native type. Calling the selection rich glosses over XML, which sits there bolted-on, barely distinguishable from a text blob without the operators a real type should have and proper indexing support in practice.
If you actually need XML queries, you're stuck parsing it as text and reaching for lxml in the app instead of a decent index in postgres. The native types are mostly solid, but serial/bigserial being presented like real types still trips everyone up, it's just a sequence under the hood!
XML actually has xpath, XMLTABLE and GIN options if you stop treating it as text, docs cover that. And yeah serial is just shorthand for integer plus a sequence with owned nextval default. Use GENERATED ALWAYS AS IDENTITY instead, it behaves, respects permissions and doesn't leave orphan sequences everywhere.
why not generated always identity?!
Casting to xml still validates well-formedness, unlike text, and xpath() plus xmlparse and xmlforest handle queries and extraction adequately. Indexing via expression indexes on xpath values works in practice for document-style access.
"Rich set" is generous when numeric vs money vs float footguns are still everywhere. Why pretend listing every type equals usability when precision traps remain?
CREATE TYPE domains save side project validation headaches.
CREATE TYPE and domains add plumbing without solving validation where it matters. The security worry about inet is overblown anyway; its parsing is well tested in core and has been for years. Using built-in types with a check constraint is simpler than rolling your own type and owning its input functions.
> its parsing is well tested in core
In practice inet accepts formats my apps never send, and macaddr8 handling improved asset tracking once we stopped normalizing it to text and a check constraint. Why would you throw that away?
time span has always sounded like a sci-fi feature for temporal tables, right on par with warp drive and dilithium crystals. Checking the docs, it is just interval dressed up for a Star Trek convention, no flux capacitor required for storage.
Untrusted inet input reaching queries risks bypassing allowlist checks!
those geometric types, paths and circles especially, feel like leftovers nobody actually uses. has anyone here ever shipped something that really needed them instead of postgis?
The line about alternative names listed in the tables being recognized has always tripped me up in practice.
When you have int vs integer vs int4, or double precision vs float8 vs float, which of those does the parser treat as the canonical type name internally, and which are just aliases resolved at parse time? It matters when you query pg_type or information_schema.columns and get something back different from what you declared in CREATE TABLE.
Is there a reliable rule for which spelling will show up in a dump or in format_type output? For example, if I declare character varying(50), will pg_dump always normalize that to the same form, or does it preserve my original choice?
And separate from storage, are any of those alternative names actually the SQL standard spelling that I should prefer for portability, versus Postgres-specific shorthand that will break if I move the schema elsewhere?
'Most of the alternative names listed' are Aliases; only pg_type.typname is canonical, which dumps emit.
> only pg_type.typname is canonical
yeah and pg_dump will happily rewrite your lovingly crafted character varying(50) into that canonical form without asking. slot-14 pedantry like this is exactly why that PostgreSQL has a rich set trophy exists.
you write int, it stores int4, you get integer back from information_schema and wonder if you're losing your mind. that's not a bug, that's just postgres being helpfully consistent in its own special way.