eriknaslund

-- This works on a normal postgres install, but on RDS it errors out with something similar too:
-- ERROR:  permission denied: "RI_ConstraintTrigger_a_6654774" is a system trigger
-- It seems like rds_admin isn't admin enough...
ALTER TABLE accept_language DISABLE TRIGGER all;

-- This apparently disables all foreign keys for the current session.
-- Too bad we can't ask DMS to execute it before starting the migration.
SET session_replication_role = replica;

-- Luckily enough we can set the above thing using a so called "parameter group" in RDS.

eriknaslund

SELECT max(pg_column_size(some_column)) / 1024.0
FROM some_table;

eriknaslund

# Dump the database schema to the file schema.sql
pg_dump -h $SRC_SERVER_IP -d $DB_NAME -U $DB_USER -f dump.sql -W -s -v

# Restore the database schema into an empty database
psql -h $DST_SERVER_IP -d $DB_NAME -U $DB_USER -f dump.sql -W

eriknaslund

aws dms create-replication-task \
	--replication-task-identifier limited-lob \
	--source-endpoint-arn $SRC_ENDPOINT_ARN \
	--target-endpoint-arn $DST_ENDPOINT_ARN \
	--replication-instance-arn $RPL_SERVER_ARN \
	--migration-type full-load-and-cdc \
	--table-mappings file://limited_lob_tables.json \
	--replication-task-settings file://limited_lob_settings.json

eriknaslund

{
    "TableMappings": [
        {
            "Type": "Include",
            "SourceSchema": "public",
            "SourceTable": "%"
        },
        {
            "Type": "Exclude",
            "SourceSchema": "public",

eriknaslund

{
	"TargetMetadata": {
		"TargetSchema": "",
		"SupportLobs": true,
		"FullLobMode": false,
		"LobMaxSize": 8192,
		"LimitedSizeLobMode": true,
		"BatchApplyEnabled": false
	},
	"FullLoadSettings": {