Class: PgReindex

Inherits:
Object
  • Object
show all
Defined in:
lib/pg-reindex.rb

Constant Summary collapse

MIN_SIZE =

megabyte min, total table size

50

Instance Method Summary collapse

Constructor Details

#initialize(conf) ⇒ PgReindex

Returns a new instance of PgReindex.



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# File 'lib/pg-reindex.rb', line 7

def initialize(conf)
  cfg = {:host => conf['host'] || '127.0.0.1', :dbname => conf['database'],
         :user => conf['username'] || `whoami`.chop, :password => conf['password'] || 'password', :port => conf['port'].to_s}

  @conn = PGconn.new cfg
end

Instance Method Details

#cancel(procpid) ⇒ Object 



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# File 'lib/pg-reindex.rb', line 189

def cancel(procpid)
  @conn.exec "select pg_cancel_backend(#{procpid.to_i})"
end

#check_swap_for_pkey ⇒ Object 



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# File 'lib/pg-reindex.rb', line 78

def check_swap_for_pkey
  res = @conn.exec <<-SQL
    SELECT  proname FROM pg_catalog.pg_namespace n JOIN pg_catalog.pg_proc p ON pronamespace = n.oid
    WHERE   nspname = 'public' and proname = 'swap_for_pkey'
  SQL
  
  res.values.size == 1
end

#database_size(database) ⇒ Object 



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# File 'lib/pg-reindex.rb', line 126

def database_size(database)
  res = @conn.exec("SELECT pg_size_pretty(pg_database_size('#{database}')) as db_size")
  res.first['db_size']
end

#exec(sql) ⇒ Object 



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# File 'lib/pg-reindex.rb', line 174

def exec(sql)
  @conn.exec sql
end

#filter_relations(filter) ⇒ Object

filter is a string with ,



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# File 'lib/pg-reindex.rb', line 33

def filter_relations(filter) # filter is a string with ,
  return [] if !filter || filter.empty?
  
  filter = filter.split(",")

  get_raw_relations.select do |row|
    filter.include?(row['index']) || filter.include?(row['table'])
  end
end

#get_index_size(relation_name) ⇒ Object 



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# File 'lib/pg-reindex.rb', line 65

def get_index_size(relation_name)
  res = @conn.exec "SELECT pg_relation_size(oid) as i_size, pg_size_pretty(pg_relation_size(oid)) as i_size_p 
                      from pg_class WHERE relname = E'#{relation_name}'"
  res[0]
rescue 
  {}
end

#get_raw_relations ⇒ Object 



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# File 'lib/pg-reindex.rb', line 43

def get_raw_relations
  res = @conn.exec <<-SQL
    SELECT C.relname AS "table",
      i.relname "index",
      i.oid "index_oid",
      pg_relation_size(C.oid) AS "size",
      pg_total_relation_size(C.oid) AS "total_size",
      pg_size_pretty(pg_relation_size(C.oid)) AS "size_p",
      pg_size_pretty(pg_total_relation_size(C.oid)) AS "total_size_p",
      pg_size_pretty(pg_total_relation_size(C.oid) - pg_relation_size(C.oid)) AS "total_i_size_p",
      pg_relation_size(i.oid) as "i_size",
      pg_size_pretty(pg_relation_size(i.oid)) as "i_size_p"
    FROM pg_class C, pg_class i, pg_index ix, pg_namespace N
    WHERE nspname IN ('public') AND
            C.oid = ix.indrelid and i.oid = ix.indexrelid
            AND C.oid = ix.indrelid and i.oid = ix.indexrelid
            AND C.relname not like 'pg_%'
            AND N.oid = C.relnamespace
    ORDER BY c.relname, i.relname
  SQL
end

#get_struct_relations(min_size = nil) ⇒ Object 



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# File 'lib/pg-reindex.rb', line 14

def get_struct_relations(min_size = nil)
  res = get_raw_relations
 
  result = {}
  res.each do |row|
    next if row['total_size'].to_i < ((min_size || MIN_SIZE).to_f * 1024 * 1024).to_i
    result[row['table']] ||= []
    result[row['table']] << row
  end
 
  result = result.sort_by{|el| el[1][0]['total_size'].to_i}.reverse
   
  result = result.map do |table, res|
    [table, res]
  end
  
  result
end

#index_def(oid) ⇒ Object 



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# File 'lib/pg-reindex.rb', line 169

def index_def(oid)
  sql = "SELECT pg_get_indexdef(#{oid}) as q"
  exec(sql)[0]['q']
end

#index_sql(table, oid, name, new_name) ⇒ Object 



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# File 'lib/pg-reindex.rb', line 158

def index_sql(table, oid, name, new_name)
  str = index_def(oid).gsub(name, new_name)
  
  pos = str.index(new_name)
          
  before = str[0..pos-2]
  after = str[pos..-1]
                     
  "#{before} CONCURRENTLY #{after}"
end

#index_sql_array(table, oid, name) ⇒ Object 



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# File 'lib/pg-reindex.rb', line 135

def index_sql_array(table, oid, name)
  new_name = if name.size < 61  
    name + "_2"
  else
    name[0..-3] + "_2"
  end
  
  if name.end_with?('_pkey')
    [
      index_sql(table, oid, name, new_name),
      "ANALYZE #{table}",
      "SELECT swap_for_pkey('public', '#{name}', '#{new_name}')"
    ]
  else
    [
      index_sql(table, oid, name, new_name),
      "ANALYZE #{table}",
      "DROP INDEX #{name}",
      "ALTER INDEX #{new_name} RENAME TO #{name}"
    ]
  end
end

#index_sqls(index_row) ⇒ Object 



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# File 'lib/pg-reindex.rb', line 131

def index_sqls(index_row)
  index_sql_array(index_row['table'], index_row['index_oid'], index_row['index'])
end

#install_swap_for_pkey ⇒ Object 



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# File 'lib/pg-reindex.rb', line 73

def install_swap_for_pkey
  @conn.exec("create language plpgsql") rescue nil
  @conn.exec(swap_for_pkey_sql)
end

#queries ⇒ Object 



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# File 'lib/pg-reindex.rb', line 178

def queries
  @conn.exec <<-SQL
  SELECT procpid,  now() - query_start as age, current_query
  FROM
      pg_stat_activity AS a JOIN
      pg_locks AS l ON a.procpid = l.pid
  WHERE 
      virtualxid IS NOT NULL order by age desc;
  SQL
end

#swap_for_pkey_sql ⇒ Object 



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# File 'lib/pg-reindex.rb', line 87

def swap_for_pkey_sql
  <<-SQL
CREATE OR REPLACE FUNCTION swap_for_pkey(text,text,text) returns integer
AS  
$$  
 DECLARE  
   cmd text;  
   oid1 integer;  
   oid2 integer;  
   filenode1 integer;  
   filenode2 integer;  
   relation text;  
 BEGIN  
    select oid::integer into oid1 from pg_class where relname=$2 and relnamespace = (select oid from pg_namespace where nspname=$1);  
   RAISE NOTICE 'PKEY OID: %',oid1;  
    select relfilenode::integer into filenode1 from pg_class where oid=oid1;  
    select oid::integer into oid2 from pg_class where relname=$3 and relnamespace = (select oid from pg_namespace where nspname=$1);  
   RAISE NOTICE 'PKEY OID: %',oid2;  
    select relfilenode::integer into filenode2 from pg_class where oid=oid2;  
    select (indrelid::regclass)::text into relation from pg_index where indexrelid=oid1;  
  RAISE NOTICE 'RELATION NAME: %',relation;  
    cmd:='LOCK '||relation||';';  
    RAISE NOTICE 'Executing :- %',cmd;  
    Execute cmd;        
    cmd:='UPDATE pg_class SET relfilenode='||filenode2|| ' WHERE oid='||oid1||';';  
    RAISE NOTICE 'Executing :- %',cmd;  
    Execute cmd;        
    cmd:='UPDATE pg_class SET relfilenode='||filenode1|| ' WHERE oid='||oid2||';';  
    RAISE NOTICE 'Executing :- %',cmd;  
    Execute cmd;  
    cmd:='DROP INDEX '||$1||'.'||$3||';';  
    RAISE NOTICE 'Executing :- %',cmd;  
    Execute cmd;  
    return 0;  
 END;  
$$language plpgsql;  
  SQL
end