module Sequel::Postgres::DatabaseMethods

  1. lib/sequel/adapters/shared/postgres.rb

Constants

DATABASE_ERROR_REGEXPS = [ # Add this check first, since otherwise it's possible for users to control # which exception class is generated. [/invalid input syntax/, DatabaseError], [/duplicate key value violates unique constraint/, UniqueConstraintViolation], [/violates foreign key constraint/, ForeignKeyConstraintViolation], [/violates check constraint/, CheckConstraintViolation], [/violates not-null constraint/, NotNullConstraintViolation], [/conflicting key value violates exclusion constraint/, ExclusionConstraintViolation], [/could not serialize access/, SerializationFailure], [/could not obtain lock on row in relation/, DatabaseLockTimeout], ].freeze  
FOREIGN_KEY_LIST_ON_DELETE_MAP = {'a'=>:no_action, 'r'=>:restrict, 'c'=>:cascade, 'n'=>:set_null, 'd'=>:set_default}.freeze  
MAX_DATE = Date.new(5874897, 12, 31)  
MAX_TIMESTAMP = (Time.utc(294277) - Rational(1, 1000000)).freeze  
MIN_DATE = Date.new(-4713, 11, 24)  
MIN_TIMESTAMP = Time.utc(-4713, 11, 24).freeze  
ON_COMMIT = {:drop => 'DROP', :delete_rows => 'DELETE ROWS', :preserve_rows => 'PRESERVE ROWS'}.freeze  
SELECT_CUSTOM_SEQUENCE_SQL = (<<-end_sql SELECT name.nspname AS "schema", CASE WHEN split_part(pg_get_expr(def.adbin, attr.attrelid), '''', 2) ~ '.' THEN substr(split_part(pg_get_expr(def.adbin, attr.attrelid), '''', 2), strpos(split_part(pg_get_expr(def.adbin, attr.attrelid), '''', 2), '.')+1) ELSE split_part(pg_get_expr(def.adbin, attr.attrelid), '''', 2) END AS "sequence" FROM pg_class t JOIN pg_namespace name ON (t.relnamespace = name.oid) JOIN pg_attribute attr ON (t.oid = attrelid) JOIN pg_attrdef def ON (adrelid = attrelid AND adnum = attnum) JOIN pg_constraint cons ON (conrelid = adrelid AND adnum = conkey[1]) WHERE cons.contype = 'p' AND pg_get_expr(def.adbin, attr.attrelid) ~* 'nextval' end_sql ).strip.gsub(/\s+/, ' ').freeze  

SQL fragment for custom sequences (ones not created by serial primary key), Returning the schema and literal form of the sequence name, by parsing the column defaults table.
SELECT_PK_SQL = (<<-end_sql SELECT pg_attribute.attname AS pk FROM pg_class, pg_attribute, pg_index, pg_namespace WHERE pg_class.oid = pg_attribute.attrelid AND pg_class.relnamespace = pg_namespace.oid AND pg_class.oid = pg_index.indrelid AND pg_index.indkey[0] = pg_attribute.attnum AND pg_index.indisprimary = 't' end_sql ).strip.gsub(/\s+/, ' ').freeze  

SQL fragment for determining primary key column for the given table. Only returns the first primary key if the table has a composite primary key.
SELECT_SERIAL_SEQUENCE_SQL = (<<-end_sql SELECT name.nspname AS "schema", seq.relname AS "sequence" FROM pg_class seq, pg_attribute attr, pg_depend dep, pg_namespace name, pg_constraint cons, pg_class t WHERE seq.oid = dep.objid AND seq.relnamespace = name.oid AND seq.relkind = 'S' AND attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid AND attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1] AND attr.attrelid = t.oid AND cons.contype = 'p' end_sql ).strip.gsub(/\s+/, ' ').freeze  

SQL fragment for getting sequence associated with table’s primary key, assuming it was a serial primary key column.
TYPTYPE_METHOD_MAP = { 'c' => :schema_composite_type, 'e' => :schema_enum_type, 'r' => :schema_range_type, 'm' => :schema_multirange_type, }  
VALID_CLIENT_MIN_MESSAGES = %w'DEBUG5 DEBUG4 DEBUG3 DEBUG2 DEBUG1 LOG NOTICE WARNING ERROR FATAL PANIC'.freeze.each(&:freeze)  

Attributes

conversion_procs [R]

A hash of conversion procs, keyed by type integer (oid) and having callable values for the conversion proc for that type.

Public Instance methods

add_conversion_proc(oid, callable=nil, &block)

Set a conversion proc for the given oid. The callable can be passed either as a argument or a block.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
320 def add_conversion_proc(oid, callable=nil, &block)
321   conversion_procs[oid] = callable || block
322 end
add_named_conversion_proc(name, &block)

Add a conversion proc for a named type, using the given block. This should be used for types without fixed OIDs, which includes all types that are not included in a default PostgreSQL installation.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
327 def add_named_conversion_proc(name, &block)
328   unless oid = from(:pg_type).where(:typtype=>['b', 'e'], :typname=>name.to_s).get(:oid)
329     raise Error, "No matching type in pg_type for #{name.inspect}"
330   end
331   add_conversion_proc(oid, block)
332 end
check_constraints(table)

A hash of metadata for CHECK constraints on the table. Keys are CHECK constraint name symbols. Values are hashes with the following keys:

:definition

An SQL fragment for the definition of the constraint

:columns

An array of column symbols for the columns referenced in the constraint, can be an empty array if the database cannot deteremine the column symbols.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
343 def check_constraints(table)
344   m = output_identifier_meth
345 
346   hash = {}
347   _check_constraints_ds.where_each(:conrelid=>regclass_oid(table)) do |row|
348     constraint = m.call(row[:constraint])
349     entry = hash[constraint] ||= {:definition=>row[:definition], :columns=>[], :validated=>row[:validated], :enforced=>row[:enforced]}
350     entry[:columns] << m.call(row[:column]) if row[:column]
351   end
352   
353   hash
354 end
commit_prepared_transaction(transaction_id, opts=OPTS)
[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
334 def commit_prepared_transaction(transaction_id, opts=OPTS)
335   run("COMMIT PREPARED #{literal(transaction_id)}", opts)
336 end
convert_serial_to_identity(table, opts=OPTS)

Convert the first primary key column in the table from being a serial column to being an identity column. If the column is already an identity column, assume it was already converted and make no changes.

Only supported on PostgreSQL 10.2+, since on those versions Sequel will use identity columns instead of serial columns for auto incrementing primary keys. Only supported when running as a superuser, since regular users cannot modify system tables, and there is no way to keep an existing sequence when changing an existing column to be an identity column.

This method can raise an exception in at least the following cases where it may otherwise succeed (there may be additional cases not listed here):

  • The serial column was added after table creation using PostgreSQL <7.3

  • A regular index also exists on the column (such an index can probably be dropped as the primary key index should suffice)

Options:

:column

Specify the column to convert instead of using the first primary key column

:server

Run the SQL on the given server

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
374 def convert_serial_to_identity(table, opts=OPTS)
375   raise Error, "convert_serial_to_identity is only supported on PostgreSQL 10.2+" unless server_version >= 100002
376 
377   server = opts[:server]
378   server_hash = server ? {:server=>server} : OPTS
379   ds = dataset
380   ds = ds.server(server) if server
381 
382   raise Error, "convert_serial_to_identity requires superuser permissions" unless ds.get{current_setting('is_superuser')} == 'on'
383 
384   table_oid = regclass_oid(table)
385   im = input_identifier_meth
386   unless column = (opts[:column] || ((sch = schema(table).find{|_, sc| sc[:primary_key] && sc[:auto_increment]}) && sch[0]))
387     raise Error, "could not determine column to convert from serial to identity automatically"
388   end
389   column = im.call(column)
390 
391   column_num = ds.from(:pg_attribute).
392     where(:attrelid=>table_oid, :attname=>column).
393     get(:attnum)
394 
395   pg_class = Sequel.cast('pg_class', :regclass)
396   res = ds.from(:pg_depend).
397     where(:refclassid=>pg_class, :refobjid=>table_oid, :refobjsubid=>column_num, :classid=>pg_class, :objsubid=>0, :deptype=>%w'a i').
398     select_map([:objid, Sequel.as({:deptype=>'i'}, :v)])
399 
400   case res.length
401   when 0
402     raise Error, "unable to find related sequence when converting serial to identity"
403   when 1
404     seq_oid, already_identity = res.first
405   else
406     raise Error, "more than one linked sequence found when converting serial to identity"
407   end
408 
409   return if already_identity
410 
411   transaction(server_hash) do
412     run("ALTER TABLE #{quote_schema_table(table)} ALTER COLUMN #{quote_identifier(column)} DROP DEFAULT", server_hash)
413 
414     ds.from(:pg_depend).
415       where(:classid=>pg_class, :objid=>seq_oid, :objsubid=>0, :deptype=>'a').
416       update(:deptype=>'i')
417 
418     ds.from(:pg_attribute).
419       where(:attrelid=>table_oid, :attname=>column).
420       update(:attidentity=>'d')
421   end
422 
423   remove_cached_schema(table)
424   nil
425 end
create_function(name, definition, opts=OPTS)

Creates the function in the database. Arguments:

name

name of the function to create

definition

string definition of the function, or object file for a dynamically loaded C function.

opts

options hash:

:args

function arguments, can be either a symbol or string specifying a type or an array of 1-3 elements:

1

argument data type

2

argument name

3

argument mode (e.g. in, out, inout)

:behavior

Should be IMMUTABLE, STABLE, or VOLATILE. PostgreSQL assumes VOLATILE by default.

:parallel

The thread safety attribute of the function. Should be SAFE, UNSAFE, RESTRICTED. PostgreSQL assumes UNSAFE by default.

:cost

The estimated cost of the function, used by the query planner.

:language

The language the function uses. SQL is the default.

:link_symbol

For a dynamically loaded see function, the function’s link symbol if different from the definition argument.

:returns

The data type returned by the function. If you are using OUT or INOUT argument modes, this is ignored. Otherwise, if this is not specified, void is used by default to specify the function is not supposed to return a value.

:rows

The estimated number of rows the function will return. Only use if the function returns SETOF something.

:security_definer

Makes the privileges of the function the same as the privileges of the user who defined the function instead of the privileges of the user who runs the function. There are security implications when doing this, see the PostgreSQL documentation.

:set

Configuration variables to set while the function is being run, can be a hash or an array of two pairs. search_path is often used here if :security_definer is used.

:strict

Makes the function return NULL when any argument is NULL.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
448 def create_function(name, definition, opts=OPTS)
449   self << create_function_sql(name, definition, opts)
450 end
create_language(name, opts=OPTS)

Create the procedural language in the database. Arguments:

name

Name of the procedural language (e.g. plpgsql)

opts

options hash:

:handler

The name of a previously registered function used as a call handler for this language.

:replace

Replace the installed language if it already exists (on PostgreSQL 9.0+).

:trusted

Marks the language being created as trusted, allowing unprivileged users to create functions using this language.

:validator

The name of previously registered function used as a validator of functions defined in this language.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
459 def create_language(name, opts=OPTS)
460   self << create_language_sql(name, opts)
461 end
create_schema(name, opts=OPTS)

Create a schema in the database. Arguments:

name

Name of the schema (e.g. admin)

opts

options hash:

:if_not_exists

Don’t raise an error if the schema already exists (PostgreSQL 9.3+)

:owner

The owner to set for the schema (defaults to current user if not specified)

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
468 def create_schema(name, opts=OPTS)
469   self << create_schema_sql(name, opts)
470 end
create_table(name, options=OPTS, &block)

Support partitions of tables using the :partition_of option.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
473 def create_table(name, options=OPTS, &block)
474   if options[:partition_of]
475     create_partition_of_table_from_generator(name, CreatePartitionOfTableGenerator.new(&block), options)
476     return
477   end
478 
479   super
480 end
create_table?(name, options=OPTS, &block)

Support partitions of tables using the :partition_of option.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
483 def create_table?(name, options=OPTS, &block)
484   if options[:partition_of]
485     create_table(name, options.merge!(:if_not_exists=>true), &block)
486     return
487   end
488 
489   super
490 end
create_trigger(table, name, function, opts=OPTS)

Create a trigger in the database. Arguments:

table

the table on which this trigger operates

name

the name of this trigger

function

the function to call for this trigger, which should return type trigger.

opts

options hash:

:after

Calls the trigger after execution instead of before.

:args

An argument or array of arguments to pass to the function.

:each_row

Calls the trigger for each row instead of for each statement.

:events

Can be :insert, :update, :delete, or an array of any of those. Calls the trigger whenever that type of statement is used. By default, the trigger is called for insert, update, or delete.

:replace

Replace the trigger with the same name if it already exists (PostgreSQL 14+).

:when

A filter to use for the trigger

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
504 def create_trigger(table, name, function, opts=OPTS)
505   self << create_trigger_sql(table, name, function, opts)
506 end
database_type()
[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
508 def database_type
509   :postgres
510 end
defer_constraints(opts=OPTS)

For constraints that are deferrable, defer constraints until transaction commit. Options:

:constraints

An identifier of the constraint, or an array of identifiers for constraints, to apply this change to specific constraints.

:server

The server/shard on which to run the query.

Examples:

DB.defer_constraints
# SET CONSTRAINTS ALL DEFERRED

DB.defer_constraints(constraints: [:c1, Sequel[:sc][:c2]])
# SET CONSTRAINTS "c1", "sc"."s2" DEFERRED
[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
527 def defer_constraints(opts=OPTS)
528   _set_constraints(' DEFERRED', opts)
529 end
do(code, opts=OPTS)

Use PostgreSQL’s DO syntax to execute an anonymous code block. The code should be the literal code string to use in the underlying procedural language. Options:

:language

The procedural language the code is written in. The PostgreSQL default is plpgsql. Can be specified as a string or a symbol.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
536 def do(code, opts=OPTS)
537   language = opts[:language]
538   run "DO #{"LANGUAGE #{literal(language.to_s)} " if language}#{literal(code)}"
539 end
drop_function(name, opts=OPTS)

Drops the function from the database. Arguments:

name

name of the function to drop

opts

options hash:

:args

The arguments for the function. See create_function_sql.

:cascade

Drop other objects depending on this function.

:if_exists

Don’t raise an error if the function doesn’t exist.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
547 def drop_function(name, opts=OPTS)
548   self << drop_function_sql(name, opts)
549 end
drop_language(name, opts=OPTS)

Drops a procedural language from the database. Arguments:

name

name of the procedural language to drop

opts

options hash:

:cascade

Drop other objects depending on this function.

:if_exists

Don’t raise an error if the function doesn’t exist.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
556 def drop_language(name, opts=OPTS)
557   self << drop_language_sql(name, opts)
558 end
drop_schema(name, opts=OPTS)

Drops a schema from the database. Arguments:

name

name of the schema to drop

opts

options hash:

:cascade

Drop all objects in this schema.

:if_exists

Don’t raise an error if the schema doesn’t exist.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
565 def drop_schema(name, opts=OPTS)
566   self << drop_schema_sql(name, opts)
567 end
drop_trigger(table, name, opts=OPTS)

Drops a trigger from the database. Arguments:

table

table from which to drop the trigger

name

name of the trigger to drop

opts

options hash:

:cascade

Drop other objects depending on this function.

:if_exists

Don’t raise an error if the function doesn’t exist.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
575 def drop_trigger(table, name, opts=OPTS)
576   self << drop_trigger_sql(table, name, opts)
577 end
foreign_key_list(table, opts=OPTS)

Return full foreign key information using the pg system tables, including :name, :on_delete, :on_update, and :deferrable entries in the hashes.

Supports additional options:

:reverse

Instead of returning foreign keys in the current table, return foreign keys in other tables that reference the current table.

:schema

Set to true to have the :table value in the hashes be a qualified identifier. Set to false to use a separate :schema value with the related schema. Defaults to whether the given table argument is a qualified identifier.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
589 def foreign_key_list(table, opts=OPTS)
590   m = output_identifier_meth
591   schema, _ = opts.fetch(:schema, schema_and_table(table))
592 
593   h = {}
594   fklod_map = FOREIGN_KEY_LIST_ON_DELETE_MAP 
595   reverse = opts[:reverse]
596 
597   (reverse ? _reverse_foreign_key_list_ds : _foreign_key_list_ds).where_each(Sequel[:cl][:oid]=>regclass_oid(table)) do |row|
598     if reverse
599       key = [row[:schema], row[:table], row[:name]]
600     else
601       key = row[:name]
602     end
603 
604     if r = h[key]
605       r[:columns] << m.call(row[:column])
606       r[:key] << m.call(row[:refcolumn])
607     else
608       entry = h[key] = {
609         :name=>m.call(row[:name]),
610         :columns=>[m.call(row[:column])],
611         :key=>[m.call(row[:refcolumn])],
612         :on_update=>fklod_map[row[:on_update]],
613         :on_delete=>fklod_map[row[:on_delete]],
614         :deferrable=>row[:deferrable],
615         :validated=>row[:validated],
616         :enforced=>row[:enforced],
617         :table=>schema ? SQL::QualifiedIdentifier.new(m.call(row[:schema]), m.call(row[:table])) : m.call(row[:table]),
618       }
619 
620       unless schema
621         # If not combining schema information into the :table entry
622         # include it as a separate entry.
623         entry[:schema] = m.call(row[:schema])
624       end
625     end
626   end
627 
628   h.values
629 end
freeze()
[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
631 def freeze
632   server_version
633   supports_prepared_transactions?
634   _schema_ds
635   _select_serial_sequence_ds
636   _select_custom_sequence_ds
637   _select_pk_ds
638   _indexes_ds
639   _check_constraints_ds
640   _foreign_key_list_ds
641   _reverse_foreign_key_list_ds
642   @conversion_procs.freeze
643   super
644 end
immediate_constraints(opts=OPTS)

Immediately apply deferrable constraints.

:constraints

An identifier of the constraint, or an array of identifiers for constraints, to apply this change to specific constraints.

:server

The server/shard on which to run the query.

Examples:

DB.immediate_constraints
# SET CONSTRAINTS ALL IMMEDIATE

DB.immediate_constraints(constraints: [:c1, Sequel[:sc][:c2]])
# SET CONSTRAINTS "c1", "sc"."s2" IMMEDIATE
[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
660 def immediate_constraints(opts=OPTS)
661   _set_constraints(' IMMEDIATE', opts)
662 end
indexes(table, opts=OPTS)

Use the pg_* system tables to determine indexes on a table

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
665 def indexes(table, opts=OPTS)
666   m = output_identifier_meth
667   cond = {Sequel[:tab][:oid]=>regclass_oid(table, opts)}
668   cond[:indpred] = nil unless opts[:include_partial]
669 
670   indexes = {}
671   _indexes_ds.where_each(cond) do |r|
672     i = indexes[m.call(r[:name])] ||= {:columns=>[], :unique=>r[:unique], :deferrable=>r[:deferrable]}
673     i[:columns] << m.call(r[:column])
674   end
675   indexes
676 end
locks()

Dataset containing all current database locks

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
679 def locks
680   dataset.from(:pg_class).join(:pg_locks, :relation=>:relfilenode).select{[pg_class[:relname], Sequel::SQL::ColumnAll.new(:pg_locks)]}
681 end
notify(channel, opts=OPTS)

Notifies the given channel. See the PostgreSQL NOTIFY documentation. Options:

:payload

The payload string to use for the NOTIFY statement. Only supported in PostgreSQL 9.0+.

:server

The server to which to send the NOTIFY statement, if the sharding support is being used.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
689 def notify(channel, opts=OPTS)
690   sql = String.new
691   sql << "NOTIFY "
692   dataset.send(:identifier_append, sql, channel)
693   if payload = opts[:payload]
694     sql << ", "
695     dataset.literal_append(sql, payload.to_s)
696   end
697   execute_ddl(sql, opts)
698 end
primary_key(table, opts=OPTS)

Return primary key for the given table.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
701 def primary_key(table, opts=OPTS)
702   quoted_table = quote_schema_table(table)
703   Sequel.synchronize{return @primary_keys[quoted_table] if @primary_keys.has_key?(quoted_table)}
704   value = _select_pk_ds.where_single_value(Sequel[:pg_class][:oid] => regclass_oid(table, opts))
705   Sequel.synchronize{@primary_keys[quoted_table] = value}
706 end
primary_key_sequence(table, opts=OPTS)

Return the sequence providing the default for the primary key for the given table.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
709 def primary_key_sequence(table, opts=OPTS)
710   quoted_table = quote_schema_table(table)
711   Sequel.synchronize{return @primary_key_sequences[quoted_table] if @primary_key_sequences.has_key?(quoted_table)}
712   cond = {Sequel[:t][:oid] => regclass_oid(table, opts)}
713   value = if pks = _select_serial_sequence_ds.first(cond)
714     literal(SQL::QualifiedIdentifier.new(pks[:schema], pks[:sequence]))
715   elsif pks = _select_custom_sequence_ds.first(cond)
716     literal(SQL::QualifiedIdentifier.new(pks[:schema], LiteralString.new(pks[:sequence])))
717   end
718 
719   Sequel.synchronize{@primary_key_sequences[quoted_table] = value} if value
720 end
refresh_view(name, opts=OPTS)

Refresh the materialized view with the given name.

DB.refresh_view(:items_view)
# REFRESH MATERIALIZED VIEW items_view
DB.refresh_view(:items_view, concurrently: true)
# REFRESH MATERIALIZED VIEW CONCURRENTLY items_view
[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
728 def refresh_view(name, opts=OPTS)
729   run "REFRESH MATERIALIZED VIEW#{' CONCURRENTLY' if opts[:concurrently]} #{quote_schema_table(name)}"
730 end
reset_primary_key_sequence(table)

Reset the primary key sequence for the given table, basing it on the maximum current value of the table’s primary key.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
734 def reset_primary_key_sequence(table)
735   return unless seq = primary_key_sequence(table)
736   pk = SQL::Identifier.new(primary_key(table))
737   db = self
738   s, t = schema_and_table(table)
739   table = Sequel.qualify(s, t) if s
740 
741   if server_version >= 100000
742     seq_ds = metadata_dataset.from(:pg_sequence).where(:seqrelid=>regclass_oid(LiteralString.new(seq)))
743     increment_by = :seqincrement
744     min_value = :seqmin
745   # :nocov:
746   else
747     seq_ds = metadata_dataset.from(LiteralString.new(seq))
748     increment_by = :increment_by
749     min_value = :min_value
750   # :nocov:
751   end
752 
753   get{setval(seq, db[table].select(coalesce(max(pk)+seq_ds.select(increment_by), seq_ds.select(min_value))), false)}
754 end
rollback_prepared_transaction(transaction_id, opts=OPTS)
[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
756 def rollback_prepared_transaction(transaction_id, opts=OPTS)
757   run("ROLLBACK PREPARED #{literal(transaction_id)}", opts)
758 end
serial_primary_key_options()

PostgreSQL uses SERIAL psuedo-type instead of AUTOINCREMENT for managing incrementing primary keys.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
762 def serial_primary_key_options
763   # :nocov:
764   auto_increment_key = server_version >= 100002 ? :identity : :serial
765   # :nocov:
766   {:primary_key => true, auto_increment_key => true, :type=>Integer}
767 end
server_version(server=nil)

The version of the PostgreSQL server, used for determining capability.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
770 def server_version(server=nil)
771   return @server_version if @server_version
772   ds = dataset
773   ds = ds.server(server) if server
774   @server_version = swallow_database_error{ds.with_sql("SELECT CAST(current_setting('server_version_num') AS integer) AS v").single_value} || 0
775 end
supports_create_table_if_not_exists?()

PostgreSQL supports CREATE TABLE IF NOT EXISTS on 9.1+

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
778 def supports_create_table_if_not_exists?
779   server_version >= 90100
780 end
supports_deferrable_constraints?()

PostgreSQL 9.0+ supports some types of deferrable constraints beyond foreign key constraints.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
783 def supports_deferrable_constraints?
784   server_version >= 90000
785 end
supports_deferrable_foreign_key_constraints?()

PostgreSQL supports deferrable foreign key constraints.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
788 def supports_deferrable_foreign_key_constraints?
789   true
790 end
supports_drop_table_if_exists?()

PostgreSQL supports DROP TABLE IF EXISTS

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
793 def supports_drop_table_if_exists?
794   true
795 end
supports_partial_indexes?()

PostgreSQL supports partial indexes.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
798 def supports_partial_indexes?
799   true
800 end
supports_prepared_transactions?()

PostgreSQL supports prepared transactions (two-phase commit) if max_prepared_transactions is greater than 0.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
809 def supports_prepared_transactions?
810   return @supports_prepared_transactions if defined?(@supports_prepared_transactions)
811   @supports_prepared_transactions = self['SHOW max_prepared_transactions'].get.to_i > 0
812 end
supports_savepoints?()

PostgreSQL supports savepoints

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
815 def supports_savepoints?
816   true
817 end
supports_transaction_isolation_levels?()

PostgreSQL supports transaction isolation levels

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
820 def supports_transaction_isolation_levels?
821   true
822 end
supports_transactional_ddl?()

PostgreSQL supports transaction DDL statements.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
825 def supports_transactional_ddl?
826   true
827 end
supports_trigger_conditions?()

PostgreSQL 9.0+ supports trigger conditions.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
803 def supports_trigger_conditions?
804   server_version >= 90000
805 end
tables(opts=OPTS, &block)

Array of symbols specifying table names in the current database. The dataset used is yielded to the block if one is provided, otherwise, an array of symbols of table names is returned.

Options:

:qualify

Return the tables as Sequel::SQL::QualifiedIdentifier instances, using the schema the table is located in as the qualifier.

:schema

The schema to search

:server

The server to use

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
838 def tables(opts=OPTS, &block)
839   pg_class_relname(['r', 'p'], opts, &block)
840 end
type_supported?(type)

Check whether the given type name string/symbol (e.g. :hstore) is supported by the database.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
844 def type_supported?(type)
845   Sequel.synchronize{return @supported_types[type] if @supported_types.has_key?(type)}
846   supported = from(:pg_type).where(:typtype=>'b', :typname=>type.to_s).count > 0
847   Sequel.synchronize{return @supported_types[type] = supported}
848 end
values(v)

Creates a dataset that uses the VALUES clause:

DB.values([[1, 2], [3, 4]])
# VALUES ((1, 2), (3, 4))

DB.values([[1, 2], [3, 4]]).order(:column2).limit(1, 1)
# VALUES ((1, 2), (3, 4)) ORDER BY column2 LIMIT 1 OFFSET 1
[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
857 def values(v)
858   raise Error, "Cannot provide an empty array for values" if v.empty?
859   @default_dataset.clone(:values=>v)
860 end
views(opts=OPTS)

Array of symbols specifying view names in the current database.

Options:

:materialized

Return materialized views

:qualify

Return the views as Sequel::SQL::QualifiedIdentifier instances, using the schema the view is located in as the qualifier.

:schema

The schema to search

:server

The server to use

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
870 def views(opts=OPTS)
871   relkind = opts[:materialized] ? 'm' : 'v'
872   pg_class_relname(relkind, opts)
873 end
with_advisory_lock(lock_id, opts=OPTS)

Attempt to acquire an exclusive advisory lock with the given lock_id (which should be a 64-bit integer). If successful, yield to the block, then release the advisory lock when the block exits. If unsuccessful, raise a Sequel::AdvisoryLockError.

DB.with_advisory_lock(1347){DB.get(1)}
# SELECT pg_try_advisory_lock(1357) LIMIT 1
# SELECT 1 AS v LIMIT 1
# SELECT pg_advisory_unlock(1357) LIMIT 1

Options:

:wait

Do not raise an error, instead, wait until the advisory lock can be acquired.

[show source] 
    # File lib/sequel/adapters/shared/postgres.rb
886 def with_advisory_lock(lock_id, opts=OPTS)
887   ds = dataset
888   if server = opts[:server]
889     ds = ds.server(server)
890   end
891 
892   synchronize(server) do |c|
893     begin
894       if opts[:wait]
895         ds.get{pg_advisory_lock(lock_id)}
896         locked = true
897       else
898         unless locked = ds.get{pg_try_advisory_lock(lock_id)}
899           raise AdvisoryLockError, "unable to acquire advisory lock #{lock_id.inspect}"
900         end
901       end
902 
903       yield
904     ensure
905       ds.get{pg_advisory_unlock(lock_id)} if locked
906     end
907   end
908 end