In part one,
Migrating PostgreSQL Databases From On-Prem to the Cloud Using AWS RDS
, we showed you how to perform the migration. In this blog, we will explore some common errors that might pop up during the migration.
BACKUP ERROR: Permission Denied to Backup Schema
/usr/pgsql-10/bin/pg_dump -v source_database -h onpremdbserver.domain.com -p 5432 -U source_appuser -Fd -j 100 -f /dbbackup/10/source_database --no-owner --no-privileges
pg_dump: last built-in OID is 16383
pg_dump: reading extensions
pg_dump: identifying extension members
pg_dump: reading schemas
pg_dump: reading user-defined tables
pg_dump: [archiver (db)] query failed: ERROR: permission denied for schema source_schema
pg_dump: [archiver (db)] query was: LOCK TABLE source_schema.table1 IN ACCESS SHARE MODE
RESOLUTION – Ensure source_appuser has the proper access. I.e. in this case, source_appuser is owner
postgres=> c source_database
psql (10.5, server 10.6)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
You are now connected to database "source_database" as user "postgres".
source_database=> dn+
List of schemas
Name | Owner | Access privileges | Description
---------------+-----------+------------------------+------------------------
public | postgres | postgres=UC/postgres+| standard public schema
| | =UC/postgres |
source_schema | postgres | |
(2 rows)
source_database=> alter schema source_schema owner to source_appuser ;
ALTER SCHEMA
source_database=> dt source_schema.table*
List of relations
Schema | Name | Type | Owner
---------------+--------+-------+-----------
source_schema | table1 | table | postgres
source_schema | table2 | table | postgres
source_schema | table3 | table | postgres
(3 rows)
source_database=> alter table source_schema.table1 owner to source_appuser ;
ALTER TABLE
source_database=> alter table source_schema.table2 owner to source_appuser ;
ALTER TABLE
source_database=> alter table source_schema.table3 owner to source_appuser ;
ALTER TABLE
source_database=> dt source_schema.table*
List of relations
Schema | Name | Type | Owner
---------------+--------+-------+----------------
source_schema | table1 | table | source_appuser
source_schema | table2 | table | source_appuser
source_schema | table3 | table | source_appuser
(3 rows)
BACKUP ERROR: Server Version Mismatch
# Backup database...
/usr/pgsql-10/bin/pg_dump -v source_database -h onpremdbserver.domain.com -p 5432 -U source_appuser -Fd -j 100 -f /dbbackup/10/source_database --no-owner --no-privileges
pg_dump: server version: 10.6; pg_dump version: 9.6.9
pg_dump: aborting because of server version mismatch
RESOLUTION – Use correct PostgreSQL binary (i.e. /usr/pgsql-10/bin Instead of /usr/pgsql-9.6/bin)
# Backup database...
/usr/pgsql-10/bin/pg_dump -v source_database -h onpremdbserver.domain.com -p 5432 -U source_appuser -Fd -j 100 -f /dbbackup/10/source_database --no-owner --no-privileges
pg_dump: last built-in OID is 16383
pg_dump: reading extensions
pg_dump: identifying extension members
pg_dump: reading schemas
pg_dump: reading user-defined tables
pg_dump: reading user-defined functions
pg_dump: reading user-defined types
pg_dump: reading procedural languages
pg_dump: reading user-defined aggregate functions
pg_dump: reading user-defined operators
pg_dump: reading user-defined access methods
pg_dump: reading user-defined operator classes
pg_dump: reading user-defined operator families
pg_dump: reading user-defined text search parsers
pg_dump: reading user-defined text search templates
pg_dump: reading user-defined text search dictionaries
pg_dump: reading user-defined text search configurations
pg_dump: reading user-defined foreign-data wrappers
pg_dump: reading user-defined foreign servers
pg_dump: reading default privileges
pg_dump: reading user-defined collations
pg_dump: reading user-defined conversions
pg_dump: reading type casts
pg_dump: reading transforms
pg_dump: reading table inheritance information
pg_dump: reading event triggers
pg_dump: finding extension tables
pg_dump: finding inheritance relationships
pg_dump: reading column info for interesting tables
pg_dump: finding the columns and types of table "source_schema.table1"
pg_dump: finding the columns and types of table "source_schema.table2"
pg_dump: finding the columns and types of table "source_schema.table3"
pg_dump: finding default expressions of table "source_schema.table3"
pg_dump: flagging inherited columns in subtables
pg_dump: reading indexes
pg_dump: reading extended statistics
pg_dump: reading constraints
pg_dump: reading triggers
pg_dump: reading rewrite rules
pg_dump: reading policies
pg_dump: reading row security enabled for table "source_schema.table1"
pg_dump: reading policies for table "source_schema.table1"
pg_dump: reading row security enabled for table "source_schema.table2"
pg_dump: reading policies for table "source_schema.table2"
pg_dump: reading row security enabled for table "source_schema.table3_id_seq"
pg_dump: reading policies for table "source_schema.table3_id_seq"
pg_dump: reading row security enabled for table "source_schema.table3"
pg_dump: reading policies for table "source_schema.table3"
pg_dump: reading publications
pg_dump: reading publication membership
pg_dump: reading publication membership for table "source_schema.table1"
pg_dump: reading publication membership for table "source_schema.table2"
pg_dump: reading publication membership for table "source_schema.table3"
pg_dump: reading subscriptions
pg_dump: reading large objects
pg_dump: reading dependency data
pg_dump: saving encoding = UTF8
pg_dump: saving standard_conforming_strings = on
pg_dump: saving search_path =
pg_dump: saving database definition
pg_dump: dumping contents of table "source_schema.table1"
pg_dump: finished item 3797 TABLE DATA table1
pg_dump: dumping contents of table "source_schema.table3"
pg_dump: finished item 3800 TABLE DATA table3
pg_dump: dumping contents of table "source_schema.table2"
pg_dump: finished item 3798 TABLE DATA table2
RESTORATION ERROR: Must Be the Owner of Extension plpgsql
# Restore database...
/usr/pgsql-10/bin/pg_restore -v -d dest_database_newdb -hdest_dbinstance.cluster-awsrdsguid.us-east-1.rds.amazonaws.com -p5432 -U dest_rds_superuser -j 120 -Fd /dbbackup/10/source_database --no-owner --no-privileges
pg_restore: connecting to database for restore
pg_restore: processing item 3803 ENCODING ENCODING
pg_restore: processing item 3804 STDSTRINGS STDSTRINGS
pg_restore: processing item 3805 SEARCHPATH SEARCHPATH
pg_restore: processing item 3806 DATABASE source_database
pg_restore: processing item 3 SCHEMA public
pg_restore: creating SCHEMA "public"
pg_restore: processing item 3807 COMMENT SCHEMA public
pg_restore: creating COMMENT "SCHEMA public"
pg_restore: processing item 6 SCHEMA source_schema
pg_restore: creating SCHEMA "source_schema"
pg_restore: processing item 1 EXTENSION plpgsql
pg_restore: creating EXTENSION "plpgsql"
pg_restore: processing item 3808 COMMENT EXTENSION plpgsql
pg_restore: creating COMMENT "EXTENSION plpgsql"
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 3808; 0 0 COMMENT EXTENSION plpgsql
pg_restore: [archiver (db)] could not execute query: ERROR: must be owner of extension plpgsql
Command was: COMMENT ON EXTENSION plpgsql IS 'PL/pgSQL procedural language';
ERROR: permission denied to create database
RESOLUTION: RDS does not allow true super user, but the error can be ignored.
RESTORATION ERROR: Permission Denied to Drop Database
ERROR:
postgres=> drop database dest_database_newdb ;
ERROR: must be owner of database dest_database_newdb
RESOLUTION
postgres=> grant dest_rds_superuser to postgres ;
GRANT ROLE
postgres=> drop database dest_database_newdb ;
DROP DATABASE
RESTORATION ERROR: Permission Denied to Alter Role
# Grant dest_rds_superuser createdb...
/usr/pgsql-10/bin/psql -E -e postgres -hdest_dbinstance.cluster-awsrdsguid.us-east-1.rds.amazonaws.com -p5432 -Udest_rds_superuser -c"alter role dest_rds_superuser createdb"
alter role dest_rds_superuser createdb
ERROR: permission denied
RESOLUTION
postgres=> grant rds_superuser to dest_rds_superuser ;
GRANT ROLE
# Grant dest_rds_superuser createdb...
/usr/pgsql-10/bin/psql -E -e postgres -hdest_dbinstance.cluster-awsrdsguid.us-east-1.rds.amazonaws.com -p5432 -Udest_rds_superuser -c"alter role dest_rds_superuser createdb"
alter role dest_rds_superuser createdb
ALTER ROLE
RESTORATION ERROR: Permission Denied to Create Database
ERROR: permission denied to create database
RESOLUTION
RESOLUTION: Roles must have createdb privilege otherwise to avoid to the following error:
postgres=> alter role dest_rds_superuser createdb ;
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RESTORATION ERROR: Database Already Exists
# Create database...
/usr/pgsql-10/bin/psql -E -e postgres -hdest_dbinstance.cluster-awsrdsguid.us-east-1.rds.amazonaws.com -p5432 -Udest_rds_superuser -c"create database dest_database_newdb"
create database dest_database_newdb
ERROR: database "dest_database_newdb" already exists
# Restore database...
/usr/pgsql-10/bin/pg_restore -v -d dest_database_newdb -hdest_dbinstance.cluster-awsrdsguid.us-east-1.rds.amazonaws.com -p5432 -U dest_rds_superuser -j 120 -Fd /dbbackup/10/source_database --no-owner --no-privileges
pg_restore: connecting to database for restore
pg_restore: processing item 3803 ENCODING ENCODING
pg_restore: processing item 3804 STDSTRINGS STDSTRINGS
pg_restore: processing item 3805 SEARCHPATH SEARCHPATH
pg_restore: processing item 3806 DATABASE source_database
pg_restore: processing item 3 SCHEMA public
pg_restore: creating SCHEMA "public"
pg_restore: processing item 3807 COMMENT SCHEMA public
pg_restore: creating COMMENT "SCHEMA public"
pg_restore: processing item 6 SCHEMA source_schema
pg_restore: creating SCHEMA "source_schema"
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 6; 2615 20233 SCHEMA source_schema source_appuser
pg_restore: [archiver (db)] could not execute query: ERROR: schema "source_schema" already exists
Command was: CREATE SCHEMA source_schema;
pg_restore: processing item 1 EXTENSION plpgsql
pg_restore: creating EXTENSION "plpgsql"
pg_restore: processing item 3808 COMMENT EXTENSION plpgsql
pg_restore: creating COMMENT "EXTENSION plpgsql"
pg_restore: [archiver (db)] Error from TOC entry 3808; 0 0 COMMENT EXTENSION plpgsql
pg_restore: [archiver (db)] could not execute query: ERROR: must be owner of extension plpgsql
Command was: COMMENT ON EXTENSION plpgsql IS 'PL/pgSQL procedural language';
pg_restore: processing item 197 TABLE table1
pg_restore: creating TABLE "source_schema.table1"
pg_restore: [archiver (db)] Error from TOC entry 197; 1259 20234 TABLE table1 source_appuser
pg_restore: [archiver (db)] could not execute query: ERROR: relation "table1" already exists
Command was: CREATE TABLE source_schema.table1 (
id integer
pg_restore: processing item 198 TABLE table2
pg_restore: creating TABLE "source_schema.table2"
pg_restore: [archiver (db)] Error from TOC entry 198; 1259 20237 TABLE table2 source_appuser
pg_restore: [archiver (db)] could not execute query: ERROR: relation "table2" already exists
Command was: CREATE TABLE source_schema.table2 (
id integer
pg_restore: processing item 200 TABLE table3
pg_restore: creating TABLE "source_schema.table3"
pg_restore: [archiver (db)] Error from TOC entry 200; 1259 20242 TABLE table3 source_appuser
pg_restore: [archiver (db)] could not execute query: ERROR: relation "table3" already exists
Command was: CREATE TABLE source_schema.table3 (
id integer NOT NULL,
name character varying
pg_restore: processing item 199 SEQUENCE table3_id_seq
pg_restore: creating SEQUENCE "source_schema.table3_id_seq"
pg_restore: [archiver (db)] Error from TOC entry 199; 1259 20240 SEQUENCE table3_id_seq source_appuser
pg_restore: [archiver (db)] could not execute query: ERROR: relation "table3_id_seq" already exists
Command was: CREATE SEQUENCE source_schema.table3_id_seq
AS integer
START WITH 1
INCREMENT BY 1
NO MINVALUE
NO MAXVALUE
CACHE 1;
pg_restore: processing item 3809 SEQUENCE OWNED BY table3_id_seq
pg_restore: creating SEQUENCE OWNED BY "source_schema.table3_id_seq"
pg_restore: processing item 3675 DEFAULT table3 id
pg_restore: creating DEFAULT "source_schema.table3 id"
pg_restore: entering main parallel loop
pg_restore: launching item 3797 TABLE DATA table1
pg_restore: launching item 3798 TABLE DATA table2
pg_restore: launching item 3800 TABLE DATA table3
pg_restore: launching item 3810 SEQUENCE SET table3_id_seq
pg_restore: pg_restore: executing SEQUENCE SET table3_id_seq
processing data for table "source_schema.table2"
pg_restore: finished item 3798 TABLE DATA table2
pg_restore: finished item 3810 SEQUENCE SET table3_id_seq
pg_restore: processing data for table "source_schema.table3"
pg_restore: processing data for table "source_schema.table1"
pg_restore: finished item 3797 TABLE DATA table1
pg_restore: finished item 3800 TABLE DATA table3
pg_restore: finished main parallel loop
WARNING: errors ignored on restore: 6
RESOLUTION – Ensure you manually remove existing database before executing the script.
# Restore database...
/usr/pgsql-10/bin/pg_restore -v -d dest_database_newdb -hdest_dbinstance.cluster-awsrdsguid.us-east-1.rds.amazonaws.com -p5432 -U dest_rds_superuser -j 120 -Fd /dbbackup/10/source_database --no-owner --no-privileges
pg_restore: connecting to database for restore
pg_restore: processing item 3803 ENCODING ENCODING
pg_restore: processing item 3804 STDSTRINGS STDSTRINGS
pg_restore: processing item 3805 SEARCHPATH SEARCHPATH
pg_restore: processing item 3806 DATABASE source_database
pg_restore: processing item 3 SCHEMA public
pg_restore: creating SCHEMA "public"
pg_restore: processing item 3807 COMMENT SCHEMA public
pg_restore: creating COMMENT "SCHEMA public"
pg_restore: processing item 6 SCHEMA source_schema
pg_restore: creating SCHEMA "source_schema"
pg_restore: processing item 1 EXTENSION plpgsql
pg_restore: creating EXTENSION "plpgsql"
pg_restore: processing item 3808 COMMENT EXTENSION plpgsql
pg_restore: creating COMMENT "EXTENSION plpgsql"
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 3808; 0 0 COMMENT EXTENSION plpgsql
pg_restore: [archiver (db)] could not execute query: ERROR: must be owner of extension plpgsql
Command was: COMMENT ON EXTENSION plpgsql IS 'PL/pgSQL procedural language';
pg_restore: processing item 197 TABLE table1
pg_restore: creating TABLE "source_schema.table1"
pg_restore: processing item 198 TABLE table2
pg_restore: creating TABLE "source_schema.table2"
pg_restore: processing item 200 TABLE table3
pg_restore: creating TABLE "source_schema.table3"
pg_restore: processing item 199 SEQUENCE table3_id_seq
pg_restore: creating SEQUENCE "source_schema.table3_id_seq"
pg_restore: processing item 3809 SEQUENCE OWNED BY table3_id_seq
pg_restore: creating SEQUENCE OWNED BY "source_schema.table3_id_seq"
pg_restore: processing item 3675 DEFAULT table3 id
pg_restore: creating DEFAULT "source_schema.table3 id"
pg_restore: entering main parallel loop
pg_restore: launching item 3797 TABLE DATA table1
pg_restore: launching item 3798 TABLE DATA table2
pg_restore: launching item 3800 TABLE DATA table3
RESTORATION ERROR: Schema Already Exists
# Create schema...
/usr/pgsql-10/bin/psql -E -e -hdest_dbinstance.cluster-awsrdsguid.us-east-1.rds.amazonaws.com -p5432 dest_database_newdb -Udest_rds_superuser -c"create schema source_schema"
create schema source_schema
ERROR: schema "source_schema" already exists
# Restore database...
/usr/pgsql-10/bin/pg_restore -v -d dest_database_newdb -hdest_dbinstance.cluster-awsrdsguid.us-east-1.rds.amazonaws.com -p5432 -U dest_rds_superuser -j 120 -Fd /dbbackup/10/source_database --schema=source_schema --no-owner --no-privileges
pg_restore: connecting to database for restore
pg_restore: processing item 3803 ENCODING ENCODING
pg_restore: processing item 3804 STDSTRINGS STDSTRINGS
pg_restore: processing item 3805 SEARCHPATH SEARCHPATH
pg_restore: processing item 6 SCHEMA source_schema
pg_restore: processing item 197 TABLE table1
pg_restore: creating TABLE "source_schema.table1"
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 197; 1259 20234 TABLE table1 source_appuser
pg_restore: [archiver (db)] could not execute query: ERROR: relation "table1" already exists
Command was: CREATE TABLE source_schema.table1 (
id integer
pg_restore: processing item 198 TABLE table2
pg_restore: creating TABLE "source_schema.table2"
pg_restore: [archiver (db)] Error from TOC entry 198; 1259 20237 TABLE table2 source_appuser
pg_restore: [archiver (db)] could not execute query: ERROR: relation "table2" already exists
Command was: CREATE TABLE source_schema.table2 (
id integer
pg_restore: processing item 200 TABLE table3
pg_restore: creating TABLE "source_schema.table3"
pg_restore: [archiver (db)] Error from TOC entry 200; 1259 20242 TABLE table3 source_appuser
pg_restore: [archiver (db)] could not execute query: ERROR: relation "table3" already exists
Command was: CREATE TABLE source_schema.table3 (
id integer NOT NULL,
name character varying
pg_restore: processing item 199 SEQUENCE table3_id_seq
pg_restore: creating SEQUENCE "source_schema.table3_id_seq"
pg_restore: [archiver (db)] Error from TOC entry 199; 1259 20240 SEQUENCE table3_id_seq source_appuser
pg_restore: [archiver (db)] could not execute query: ERROR: relation "table3_id_seq" already exists
Command was: CREATE SEQUENCE source_schema.table3_id_seq
AS integer
START WITH 1
INCREMENT BY 1
NO MINVALUE
NO MAXVALUE
CACHE 1;
pg_restore: processing item 3806 SEQUENCE OWNED BY table3_id_seq
pg_restore: creating SEQUENCE OWNED BY "source_schema.table3_id_seq"
pg_restore: processing item 3675 DEFAULT table3 id
pg_restore: creating DEFAULT "source_schema.table3 id"
pg_restore: entering main parallel loop
pg_restore: launching item 3797 TABLE DATA table1
pg_restore: launching item 3798 TABLE DATA table2
pg_restore: launching item 3800 TABLE DATA table3
pg_restore: launching item 3807 SEQUENCE SET table3_id_seq
pg_restore: pg_restore: processing data for table "source_schema.table2"
processing data for table "source_schema.table1"
pg_restore: executing SEQUENCE SET table3_id_seq
pg_restore: finished item 3797 TABLE DATA table1
pg_restore: finished item 3798 TABLE DATA table2
pg_restore: finished item 3807 SEQUENCE SET table3_id_seq
pg_restore: processing data for table "source_schema.table3"
pg_restore: finished item 3800 TABLE DATA table3
pg_restore: finished main parallel loop
WARNING: errors ignored on restore: 4
RESOLUTION – Either drop or rename existing schema. I like renaming until all is validated:
postgres=> c dest_database_newdb
psql (10.5, server 10.6)
SSL connection (protocol: TLSv1.2, cipher: ECDHE-RSA-AES256-GCM-SHA384, bits: 256, compression: off)
You are now connected to database "dest_database_newdb" as user "postgres".
dest_database_newdb=> dn
List of schemas
Name | Owner
---------------+--------------------
public | postgres
source_schema | dest_rds_superuser
(2 rows)
dest_database_newdb=> alter schema source_schema rename to source_schema_old;
ALTER SCHEMA
dest_database_newdb=> dn
List of schemas
Name | Owner
-------------------+--------------------
public | postgres
source_schema_old | dest_rds_superuser
(2 rows)
# Restore database...
/usr/pgsql-10/bin/pg_restore -v -d dest_database_newdb -hdest_dbinstance.cluster-awsrdsguid.us-east-1.rds.amazonaws.com -p5432 -U dest_rds_superuser -j 120 -Fd /dbbackup/10/source_database --schema=source_schema --no-owner --no-privileges
pg_restore: connecting to database for restore
pg_restore: processing item 3803 ENCODING ENCODING
pg_restore: processing item 3804 STDSTRINGS STDSTRINGS
pg_restore: processing item 3805 SEARCHPATH SEARCHPATH
pg_restore: processing item 6 SCHEMA source_schema
pg_restore: processing item 197 TABLE table1
pg_restore: creating TABLE "source_schema.table1"
pg_restore: processing item 198 TABLE table2
pg_restore: creating TABLE "source_schema.table2"
pg_restore: processing item 200 TABLE table3
pg_restore: creating TABLE "source_schema.table3"
pg_restore: processing item 199 SEQUENCE table3_id_seq
pg_restore: creating SEQUENCE "source_schema.table3_id_seq"
pg_restore: processing item 3806 SEQUENCE OWNED BY table3_id_seq
pg_restore: creating SEQUENCE OWNED BY "source_schema.table3_id_seq"
pg_restore: processing item 3675 DEFAULT table3 id
pg_restore: creating DEFAULT "source_schema.table3 id"
pg_restore: entering main parallel loop
pg_restore: launching item 3797 TABLE DATA table1
pg_restore: launching item 3798 TABLE DATA table2
pg_restore: launching item 3800 TABLE DATA table3
pg_restore: launching item 3807 SEQUENCE SET table3_id_seq
pg_restore: processing data for table "source_schema.table1"
pg_restore: processing data for table "source_schema.table2"
pg_restore: executing SEQUENCE SET table3_id_seq
pg_restore: finished item 3807 SEQUENCE SET table3_id_seq
pg_restore: processing data for table "source_schema.table3"
pg_restore: finished item 3797 TABLE DATA table1
pg_restore: finished item 3798 TABLE DATA table2
pg_restore: finished item 3800 TABLE DATA table3
pg_restore: finished main parallel loop