Skip to content
pgferry

PlanetScale to Supabase

This is an operator’s playbook for a PlanetScale to Supabase migration — moving a PlanetScale (MySQL/Vitess) database into Supabase PostgreSQL with pgferry. PlanetScale’s classic product is MySQL on Vitess, so this is a cross-engine MySQL → PostgreSQL migration, with one twist: Vitess imposes connection and transaction constraints that plain self-hosted MySQL does not.

If you searched for how to migrate PlanetScale to Supabase or move PlanetScale MySQL to Supabase Postgres, the short version is: connect to PlanetScale over TLS (tls=true), be deliberate about how you take a consistent snapshot through Vitess, point pgferry at Supabase’s session pooler, and raise the postgres role statement timeout for the load.

What this guide is for

Section titled “What this guide is for”

Use this guide when your source is a PlanetScale MySQL/Vitess database and your destination is Supabase Postgres. This page is not about PlanetScale for Postgres (their newer PostgreSQL product) — here PlanetScale is the source and Supabase is the destination. For source-side type behavior that is not PlanetScale-specific (enums, sets, unsigned integers, zero dates), read the generic MySQL to PostgreSQL guide alongside this page.

Why use pgferry instead of generic pgloader advice

Section titled “Why use pgferry instead of generic pgloader advice”

Most “planetscale to postgres” advice points at pgloader, which struggles on real schemas — and PlanetScale’s own exporter targets MySQL/PlanetScale, not PostgreSQL:

  • pgloader has no resume and loads in long transactions; a drop over PlanetScale’s proxied connection means starting over. pgferry checkpoints and resumes.
  • MySQL enums, sets, unsigned integers, tinyint(1), and zero dates are explicit, documented knobs in pgferry; pgloader guesses and frequently picks text.
  • pgferry streams with chunked, parallel COPY and runs a plan preflight that surfaces skipped indexes, generated columns, and required extensions before PostgreSQL is touched.
  • pgferry creates objects as the connecting role, avoiding the ownership/SET ROLE errors pg_dump/pg_restore hit against Supabase’s non-superuser role.

Destination prerequisites

Section titled “Destination prerequisites”
  • A Supabase project (note its project ref) and the database password from Project Settings → Database.
  • Decide the target schema. Supabase uses public by default; pgferry can create and own a dedicated schema instead.
  • The Supabase postgres role is not a superuser but can create schemas, tables, indexes, FKs, sequences, and allow-listed extensions — everything pgferry needs.
Section titled “Recommended pgferry config”
schema = "app"
on_schema_exists = "error"
unlogged_tables = false
resume = true
validation = "row_count"
chunk_size = 100000
source_snapshot_mode = "single_tx"


[source]
type = "mysql"
# dsn supplied via PGFERRY_SOURCE_DSN


[target]
# dsn supplied via PGFERRY_TARGET_DSN


[type_mapping]
tinyint1_as_boolean = false
json_as_jsonb = true
enum_mode = "check"
set_mode = "text"
sanitize_json_null_bytes = true

resume = true requires unlogged_tables = false (see the configuration reference). On a Vitess source, read the snapshot caveat below before relying on single_tx.

PlanetScale source connection, TLS, and Vitess constraints

Section titled “PlanetScale source connection, TLS, and Vitess constraints”

PlanetScale connection credentials come from the database’s Connect dialog; passwords are prefixed pscale_pw_, and the direct host is typically aws.connect.psdb.cloud. pgferry uses the go-sql-driver/mysql driver, so the source DSN is:

Terminal window
export PGFERRY_SOURCE_DSN='<user>:pscale_pw_<...>@tcp(aws.connect.psdb.cloud:3306)/<db>?tls=true'
  • TLS is mandatory. PlanetScale rejects unencrypted connections (client must use SSL/TLS). Use ?tls=true — PlanetScale’s certificate chains to a public CA, so the driver verifies against the system trust store with no CA file to download.
  • Vitess is not plain MySQL. PlanetScale runs MySQL behind Vitess (VTGate). Two consequences for a migration source:
    • Stored procedures are unsupported, and foreign keys were unsupported for most of PlanetScale’s history (they require opt-in on recent versions). Your schema may have no FKs to migrate — that is expected, not a pgferry omission.
    • Connections are pooled and proxied through VTGate, which enforces query and transaction timeouts. A long-running single_tx snapshot over a very large keyspace can be cut off mid-read.
  • Snapshot strategy. For small-to-medium databases, source_snapshot_mode = "single_tx" is fine. For large ones, run the migration during a quiet window, or migrate from a branch created off production so the read load and any timeout pressure stay off your live keyspace.
  • IP restrictions are an opt-in PlanetScale feature (default open). If you have enabled them, add your migration host’s egress IP.

Supabase DSN, TLS, pooling, and firewall notes

Section titled “Supabase DSN, TLS, pooling, and firewall notes”

Supabase exposes three connection types. Database name is always postgres.

TypeHostPortUsername
Directdb.<ref>.supabase.co5432postgres
Session pooler (Supavisor)aws-0-<region>.pooler.supabase.com5432postgres.<ref>
Transaction pooler (Supavisor)aws-0-<region>.pooler.supabase.com6543postgres.<ref>
  • Use the session pooler (5432) or the direct connection. Both keep prepared statements and session state that pgferry’s COPY and DDL pipeline need.
  • Never use the transaction pooler (6543) for a migration — transaction mode disables prepared statements and drops session settings.
  • IPv4-only host? The direct connection is IPv6-only without the paid IPv4 add-on; the session pooler is IPv4-native, so prefer it. Copy the exact host from the dashboard Connect dialog.
  • TLS: use ?sslmode=require, or sslmode=verify-full&sslrootcert=... with the CA cert from Project Settings → Database → SSL Configuration.

Example session-pooler target DSN:

Terminal window
export PGFERRY_TARGET_DSN='postgresql://postgres.<ref>:<password>@aws-0-<region>.pooler.supabase.com:5432/postgres?sslmode=require'

Statement timeout — the most common Supabase migration failure

Section titled “Statement timeout — the most common Supabase migration failure”

Supabase caps the postgres role at a 2-minute statement timeout by default. A large COPY chunk or index build dies with canceling statement due to statement timeout. Disable it for the load, then restore:

alter role postgres set statement_timeout = '0';   -- before
alter role postgres reset statement_timeout;        -- after cutover

Reconnect for it to take effect.

Source-specific caveats (MySQL family)

Section titled “Source-specific caveats (MySQL family)”

PlanetScale is MySQL, so the MySQL decisions apply — decide them deliberately (full detail in the MySQL guide):

  • enum_mode / set_mode — how ENUM and SET columns land in PostgreSQL.
  • tinyint1_as_boolean — only if tinyint(1) truly means boolean in your data.
  • widen_unsigned_integers / add_unsigned_checks — preserve unsigned ranges.
  • zero_date_mode — convert 0000-00-00 to NULL or error.
  • Generated columns copy as values; FULLTEXT, prefix, and expression indexes are reported and skipped.
  • ci_as_citext = true needs the citext extension (enable it in Supabase Database → Extensions if pgferry reports it).

Step-by-step PlanetScale to Supabase migration flow

Section titled “Step-by-step PlanetScale to Supabase migration flow”
  1. Copy a PlanetScale connection string (pscale_pw_ password) and confirm tls=true connects.
  2. Decide your snapshot strategy — single_tx for small/medium data, or migrate from a branch for large keyspaces.
  3. Create the Supabase project, copy the session-pooler string, and alter role postgres set statement_timeout = '0';.
  4. Generate a config with pgferry wizard or start from the snippet above; export PGFERRY_SOURCE_DSN and PGFERRY_TARGET_DSN.
  5. Run pgferry plan migration.toml and resolve every warning (skipped indexes, generated columns, required extensions).
  6. Run pgferry migrate migration.toml; rerun on interruption (resume = true).
  7. Recreate views and triggers via hooks (PlanetScale has no stored procedures to port).

Validation and cutover checklist

Section titled “Validation and cutover checklist”
  • pgferry validate migration.toml re-runs validation without redoing DDL or COPY.
  • Confirm Supabase Database → Extensions has every extension your schema needs.
  • Spot-check enum/set columns and any tinyint(1) columns for the mapping you chose.
  • Restore the postgres role statement_timeout.
  • Walk the cutover checklist and first production migration checklist.

Common failures for this provider pair

Section titled “Common failures for this provider pair”
SymptomCauseFix
client must use SSL/TLS on the sourceMissing TLS on the PlanetScale DSNAppend ?tls=true
Source read cut off on a huge keyspaceVitess query/transaction timeout during single_txMigrate from a branch or during a quiet window
No foreign keys appear on the targetPlanetScale schema had none (Vitess default)Expected; add FKs on PostgreSQL via hooks if desired
canceling statement due to statement timeoutSupabase 2-min role timeoutalter role postgres set statement_timeout = '0'
prepared statement ... does not existConnected via transaction pooler (6543)Use session pooler (5432) or direct

See common failures and recovery.

Section titled “Related”