![]() If you map timestamp LocalDateTime you always get the same value regardless default Java application timezone. With the Java 8 date & time API I wouldn't blindly jump into a timestamptz camp. Mysql performance on 6 million row table.docker-compose mysql init sql is not executed.Mysql DATE_SUB(NOW(), INTERVAL 1 DAY) 24 hours or weekday?.mysql query: SELECT DISTINCT column1, GROUP BY column2.How to get phpmyadmin username and password.How many values in an "in" clause is too many in a SQL query?.save an object with a bidirectional relationship in mongodb using official c# driver.How to add orderby using in mongodb repository.Mongo "Unrecognized pipeline stage name: '$filter'".Can you have collection level permissions in MongoDB?.Golang reports "context deadline exceeded" with MongoDB.Mongoose: Returning unique result set with no duplicate entries.In Mongodb, how do I get the count of the total results returned, without the limit?.How to query a Array for a regexp match?.Class 'MongoDB' not found in fatfree (f3).Insert JSON into PostgreSQL database with Dapper ORM (.NET Core).PSQLException: this ResultSet is closed.How to run Postgres in a docker Alpine Linux container?.Add timezone to timestamp in PostgreSQL (not convert to this timezone). ![]() Cannot store Euro-sign into LOB String property with Hibernate/PostgreSQL.Get distinct consecutive date ranges from overlapping date ranges.How to pass a record to a PL/pgSQL function?.Why would a rails 5 upgrade drastically increase database CPU usage?.The type time with time zone is defined by the SQL standard, but the definition exhibits properties which lead to questionable usefulness. ![]() Int32 zone /* numeric time zone, in seconds */įollow the documentation and avoid time with time zone: TimeADT time /* all time units other than months and years */ See src/include/utils/date.h: typedef struct Time with time zone has an additional 4 byte integer representing the time zone offset in seconds. See src/include/utils/date.h: typedef int64 TimeADT Time without time zone is a 8 byte integer representing microseconds since midnight (a 4 byte integer wouldn't suffice). The definitions are in src/include/datatype/timestamp.h: typedef int64 Timestamp The difference is that timestamp with time zone is interpreted as being in UTC and is converted according to the current setting of the timezone parameter on display. Thus my question: How does the internal storage of these types in PostgreSQL work?īoth timestamp with time zone and timestamp without time zone are stored as an 8 byte integer representing microseconds since midnight on Jan 1 2000. If we already use 63 bits for the values there is only one bit left, which cannot be enough to store the timezone, so the internal storage must work somehow different.Įven stranger, while timestamps use only 8 bytes, time with time zone needs 12 bytes, although it has the same resolution and a much smaller range of allowed values. However, timestamp with timezone has the same range and resolution and can additonally store the time zone information. This amounts to roughly 2^63 values and those can be stored in 8 bytes. ![]() (Not accounting for calender changes and such). I can understand timestamp without time zone: There are roughly (4713 + 294276) * 365 * 24 * 60 * 60 * 1000000 microseconds between low and high value. Time with time zone 12 bytes time of day (no date), with time zone 00:00:00+1559 24:00:00-1559 1 microsecond Timestamp with time zone 8 bytes both date and time, with time zone 4713 BC 294276 AD 1 microsecond Timestamp without time zone 8 bytes both date and time (no time zone) 4713 BC 294276 AD 1 microsecond Inter alia it states: Name Storage Size Description Low Value High Value Resolution When reading the PostreSQL (13) documentation, I came across this page, which lists the storage sizes of different datetime types.
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