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Interface Support Functions45.2. Interface Support Functions
The functions described here provide an interface for extracting information from result sets returned by SPI_execute and other SPI functions.
All functions…Interface Support Functions
Interfacing Extensions to Indexes36.16. Interfacing Extensions to Indexes
The procedures described thus far let you define new types, new functions, and new operators. However, we cannot yet define an index on a column of a…Interfacing Extensions to Indexes
Interleaving Result Processing and Query Dispatch32.5.1.4. Interleaving Result Processing and Query Dispatch
To avoid deadlocks on large pipelines the client should be structured around a non-blocking event loop using operating system faci…Interleaving Result Processing and Query Dispatch
Internal Functions36.9. Internal Functions
Internal functions are functions written in C that have been statically linked into the PostgreSQL server. The “body” of the function definition specifies the C-lang…Internal Functions
Internals34.17. Internals
This section explains how ECPG works internally. This information can occasionally be useful to help users understand how to use ECPG.
The first four lines written by ecpg t…Internals
InternalsPart VII. Internals
This part contains assorted information that might be of use to PostgreSQL developers.Internals
Interpreting ResultsInterpreting Results
Good results will show most (>90%) individual timing calls take less than one microsecond. Average per loop overhead will be even lower, below 100 nanoseconds. This exam…Interpreting Results
INTERSECT ClauseINTERSECT Clause
The INTERSECT clause has this general form:
select_statement INTERSECT [ ALL | DISTINCT ] select_statement
select_statement is any SELECT statement without an ORDER BY, LIMI…INTERSECT Clause
interval34.4.4.2.2. interval
The handling of the interval type is also similar to the timestamp and date types. It is required, however, to allocate memory for an interval type value explicitly. In …interval
Interval Input8.5.4. Interval Input
interval values can be written using the following verbose syntax:
[@] quantity unit [quantity unit...] [direction]
where quantity is a number (possibly signed); unit i…Interval Input
Interval Output8.5.5. Interval Output
As previously explained, PostgreSQL stores interval values as months, days, and microseconds. For output, the months field is converted to years and months by dividing…Interval Output
Introduction65.5.1. Introduction
BRIN stands for Block Range Index. BRIN is designed for handling very large tables in which certain columns have some natural correlation with their physical location wi…Introduction
Introduction65.1.1. Introduction
PostgreSQL includes an implementation of the standard btree (multi-way balanced tree) index data structure. Any data type that can be sorted into a well-defined linear o…Introduction
Introduction65.4.1. Introduction
GIN stands for Generalized Inverted Index. GIN is designed for handling cases where the items to be indexed are composite values, and the queries to be handled by the in…Introduction
Introduction65.2.1. Introduction
GiST stands for Generalized Search Tree. It is a balanced, tree-structured access method, that acts as a base template in which to implement arbitrary indexing schemes. …Introduction
Introduction11.1. Introduction
Suppose we have a table similar to this:
CREATE TABLE test1 ( id integer, content varchar );
and the application issues many queries of the form:
SELECT content FROM test1…Introduction
Introduction33.1. Introduction
All large objects are stored in a single system table named pg_largeobject. Each large object also has an entry in the system table pg_largeobject_metadata. Large objects …Introduction
Introduction13.1. Introduction
PostgreSQL provides a rich set of tools for developers to manage concurrent access to data. Internally, data consistency is maintained by using a multiversion model (Multi…Introduction
Introduction65.3.1. Introduction
SP-GiST is an abbreviation for space-partitioned GiST. SP-GiST supports partitioned search trees, which facilitate development of a wide range of different non-balanced …Introduction
Introduction12.1. Introduction
Full Text Searching (or just text search) provides the capability to identify natural-language documents that satisfy a query, and optionally to sort them by relevance to …Introduction
Introduction3.1. Introduction
In the previous chapter we have covered the basics of using SQL to store and access your data in PostgreSQL. We will now discuss some more advanced features of SQL that sim…Introduction
Introduction2.1. Introduction
This chapter provides an overview of how to use SQL to perform simple operations. This tutorial is only intended to give you an introduction and is in no way a complete tut…Introduction
IS DOCUMENT9.15.2.1. IS DOCUMENT
xml IS DOCUMENT → boolean
The expression IS DOCUMENT returns true if the argument XML value is a proper XML document, false if it is not (that is, it is a content fragm…IS DOCUMENT
IS NOT DOCUMENT9.15.2.2. IS NOT DOCUMENT
xml IS NOT DOCUMENT → boolean
The expression IS NOT DOCUMENT returns false if the argument XML value is a proper XML document, true if it is not (that is, it is a c…IS NOT DOCUMENT
isn — data types for international standard numbers (ISBN, EAN, UPC, etc.)F.20. isn — data types for international standard numbers (ISBN, EAN, UPC, etc.)
The isn module provides data types for the following international product numbering standards: EAN13, UPC, I…isn — data types for international standard numbers (ISBN, EAN, UPC, etc.)
Ispell Dictionary12.6.5. Ispell Dictionary
The Ispell dictionary template supports morphological dictionaries, which can normalize many different linguistic forms of a word into the same lexeme. For example,…Ispell Dictionary
Issuing Queries32.5.1.1. Issuing Queries
After entering pipeline mode, the application dispatches requests using PQsendQueryParams or its prepared-query sibling PQsendQueryPrepared. These requests are queu…Issuing Queries
JIT Accelerated Operations30.1.1. JIT Accelerated Operations
Currently PostgreSQL's JIT implementation has support for accelerating expression evaluation and tuple deforming. Several other operations could be acceler…JIT Accelerated Operations
JIT Provider Interface30.4.2.1. JIT Provider Interface
A JIT provider is loaded by dynamically loading the named shared library. The normal library search path is used to locate the library. To provide the requir…JIT Provider Interface
JOIN36.15.4. JOIN
The JOIN clause, if provided, names a join selectivity estimation function for the operator. (Note that this is a function name, not an operator name.) JOIN clauses only make s…JOIN
Joined Tables7.2.1.1. Joined Tables
A joined table is a table derived from two other (real or derived) tables according to the rules of the particular join type. Inner, outer, and cross-joins are availab…Joined Tables
Joins Between Tables2.6. Joins Between Tables
Thus far, our queries have only accessed one table at a time. Queries can access multiple tables at once, or access the same table in such a way that multiple rows …Joins Between Tables
JSON Functions and Operators9.16. JSON Functions and Operators
This section describes:
functions and operators for processing and creating JSON data the SQL/JSON path language the SQL/JSON query functions
To provide na…JSON Functions and Operators
JSON Input and Output Syntax8.14.1. JSON Input and Output Syntax
The input/output syntax for the JSON data types is as specified in RFC 7159.
The following are all valid json (or jsonb) expressions:
-- Simple scalar/pr…JSON Input and Output Syntax
JSON Types8.14. JSON Types
JSON data types are for storing JSON (JavaScript Object Notation) data, as specified in RFC 7159. Such data can also be stored as text, but the JSON data types have the adva…JSON Types
JSON_TABLE9.16.4. JSON_TABLE
JSON_TABLE is an SQL/JSON function which queries JSON data and presents the results as a relational view, which can be accessed as a regular SQL table. You can use JSON_TA…JSON_TABLE
jsonb Containment and Existence8.14.3. jsonb Containment and Existence
Testing containment is an important capability of jsonb. There is no parallel set of facilities for the json type. Containment tests whether one jsonb…jsonb Containment and Existence
jsonb Indexing8.14.4. jsonb Indexing
GIN indexes can be used to efficiently search for keys or key/value pairs occurring within a large number of jsonb documents (datums). Two GIN “operator classes” are p…jsonb Indexing
jsonb Subscripting8.14.5. jsonb Subscripting
The jsonb data type supports array-style subscripting expressions to extract and modify elements. Nested values can be indicated by chaining subscripting expressio…jsonb Subscripting
jsonpath Type8.14.7. jsonpath Type
The jsonpath type implements support for the SQL/JSON path language in PostgreSQL to efficiently query JSON data. It provides a binary representation of the parsed SQL/…jsonpath Type
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