Search results
Results from the WOW.Com Content Network
In this case, if the transaction's timestamp is after the object's read timestamp, the read timestamp is set to the transaction's timestamp. If a transaction wants to write to an object, but the transaction started before the object's read timestamp it means that something has had a look at the object, and we assume it took a copy of the object ...
The Lamport timestamp algorithm is a simple logical clock algorithm used to determine the order of events in a distributed computer system.As different nodes or processes will typically not be perfectly synchronized, this algorithm is used to provide a partial ordering of events with minimal overhead, and conceptually provide a starting point for the more advanced vector clock method.
The term "timestamp" derives from rubber stamps used in offices to stamp the current date, and sometimes time, in ink on paper documents, to record when the document was received. Common examples of this type of timestamp are a postmark on a letter or the "in" and "out" times on a time card .
The following tables illustrate methods for retrieving the system time in various operating systems, programming languages, and applications. Values marked by (*) are system-dependent and may differ across implementations. All dates are given as Gregorian or proleptic Gregorian calendar dates.
The timestamp can be shifted by any time shift value. Directly after the timestamp follows the version nibble, that must have a value of 7. The variant bits have to be 10x. Remaining 74 bits are random seeded counter (optional, at least 12 bits but no longer than 42 bits) and random. Two counter rollover handling methods can be used together:
MySQL (/ ˌ m aɪ ˌ ɛ s ˌ k juː ˈ ɛ l /) [6] is an open-source relational database management system (RDBMS). [6] [7] Its name is a combination of "My", the name of co-founder Michael Widenius's daughter My, [1] and "SQL", the acronym for Structured Query Language.
The maximum value of a signed 32-bit integer is 2 31 − 1, and the minimum value is −2 31, making it impossible to represent dates before 13 December 1901 (at 20:45:52 UTC) or after 19 January 2038 (at 03:14:07 UTC). The early cutoff can have an impact on databases that are storing historical information; in some databases where 32-bit Unix ...
Conversely, PostgreSQL has applied more of the specification implementing cross-table, cross-schema, and then left room for future cross-database functionality. MySQL aliases schema with database behind the scenes, such that CREATE SCHEMA and CREATE DATABASE are analogs. It can therefore be said that MySQL has implemented cross-database ...