Class: ActiveRecord::ConnectionAdapters::PostgreSQLAdapter
- Inherits:
-
Object
- Object
- ActiveRecord::ConnectionAdapters::PostgreSQLAdapter
- Defined in:
- lib/core_ext/active_record/connection_adapters/postgresql_adapter.rb
Overview
Patched version: 3.1.3
- Patched methods
-
indexes
-
Constant Summary collapse
- INDEX_COLUMN_EXPRESSION =
Regex to find columns used in index statements
/ON \w+(?: USING \w+ )?\((.+)\)/
- INDEX_WHERE_EXPRESION =
Regex to find where clause in index statements
/WHERE (.+)$/
Instance Method Summary collapse
-
#find_column_names(table_name, index) ⇒ Array
Find column names from index attributes.
-
#find_lengths(index) ⇒ Array
Find length of index TODO Update lengths once we merge in ActiveRecord code that supports it.
-
#find_where_statement(index) ⇒ String
Find where statement from index definition.
-
#indexes(table_name, name = nil) ⇒ Object
Returns an array of indexes for the given table.
-
#remove_type(column_with_type) ⇒ String
Remove type specification from stored Postgres index definitions.
-
#split_expression(expression) ⇒ Object
Splits only on commas outside of parens.
Instance Method Details
#find_column_names(table_name, index) ⇒ Array
Find column names from index attributes. If the columns are virtual (ie this is an expression index) then it will try to return the functions that represent each column
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# File 'lib/core_ext/active_record/connection_adapters/postgresql_adapter.rb', line 76 def find_column_names(table_name, index) columns = Hash[query(<<-SQL, "Columns for index #{index[:name]} on #{table_name}")] SELECT a.attnum, a.attname FROM pg_attribute a WHERE a.attrelid = #{index[:id]} AND a.attnum IN (#{index[:keys].join(",")}) SQL column_names = columns.values_at(*index[:keys]).compact if column_names.empty? definition = index[:definition].sub(INDEX_WHERE_EXPRESION, '') if column_expression = definition.match(INDEX_COLUMN_EXPRESSION)[1] column_names = split_expression(column_expression).map do |functional_name| remove_type(functional_name) end end end column_names end |
#find_lengths(index) ⇒ Array
Find length of index TODO Update lengths once we merge in ActiveRecord code that supports it. -dresselm 20120305
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# File 'lib/core_ext/active_record/connection_adapters/postgresql_adapter.rb', line 138 def find_lengths(index) [] end |
#find_where_statement(index) ⇒ String
Find where statement from index definition
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# File 'lib/core_ext/active_record/connection_adapters/postgresql_adapter.rb', line 129 def find_where_statement(index) index[:definition].scan(INDEX_WHERE_EXPRESION).flatten[0] end |
#indexes(table_name, name = nil) ⇒ Object
Returns an array of indexes for the given table.
Patch 1 reason:
Since SchemaDumper#tables is patched to process tables with a schema prefix, the #indexes method receives table_name as “<schema>.<table>”. This patch allows it to handle table names with a schema prefix.
Patch 1:
Search using provided schema if table_name includes schema name.
Patch 2 reason:
#indexes is patched to support partial indexes using :where clause.
Patch 2:
Search the postgres indexdef for the where clause and pass the output to the custom PgPower::ConnectionAdapters::IndexDefinition
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# File 'lib/core_ext/active_record/connection_adapters/postgresql_adapter.rb', line 31 def indexes(table_name, name = nil) schema, table = Utils.extract_schema_and_table(table_name) schemas = schema ? "ARRAY['#{schema}']" : 'current_schemas(false)' result = query(<<-SQL, name) SELECT distinct i.relname, d.indisunique, d.indkey, pg_get_indexdef(d.indexrelid), t.oid, am.amname FROM pg_class t INNER JOIN pg_index d ON t.oid = d.indrelid INNER JOIN pg_class i ON d.indexrelid = i.oid INNER JOIN pg_am am ON i.relam = am.oid WHERE i.relkind = 'i' AND d.indisprimary = 'f' AND t.relname = '#{table}' AND i.relnamespace IN (SELECT oid FROM pg_namespace WHERE nspname = ANY (#{schemas}) ) ORDER BY i.relname SQL result.map do |row| index = { :name => row[0], :unique => row[1] == 't', :keys => row[2].split(" "), :definition => row[3], :id => row[4], :access_method => row[5] } column_names = find_column_names(table_name, index) unless column_names.empty? where = find_where_statement(index) lengths = find_lengths(index) PgPower::ConnectionAdapters::IndexDefinition.new(table_name, index[:name], index[:unique], column_names, lengths, where, index[:access_method]) end end.compact end |
#remove_type(column_with_type) ⇒ String
Remove type specification from stored Postgres index definitions
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# File 'lib/core_ext/active_record/connection_adapters/postgresql_adapter.rb', line 150 def remove_type(column_with_type) column_with_type.sub(/\((\w+)\)::\w+/, '\1') end |
#split_expression(expression) ⇒ Object
Splits only on commas outside of parens
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# File 'lib/core_ext/active_record/connection_adapters/postgresql_adapter.rb', line 99 def split_expression(expression) result = [] parens = 0 buffer = "" expression.chars do |char| case char when ',' if parens == 0 result.push(buffer) buffer = "" next end when '(' parens += 1 when ')' parens -= 1 end buffer << char end result << buffer unless buffer.empty? result end |