如何使用PostgreSQL 10.4 Docker镜像升级8.4版本数据库文件？

Absolutely! You can use your PostgreSQL 10.4 Docker image to upgrade your 8.4 database files—here's a practical, step-by-step method that’s worked for many developers:

Step 1: Validate your old 8.4 database files first #

Before diving into the upgrade, confirm your existing 8.4 data directory is intact (no corruption). Spin up a temporary PostgreSQL 8.4 container to test this:

docker run -d --name pg84-temp \
  -v /path/to/your/old-8.4-data:/var/lib/postgresql/data \
  postgres:8.4

Wait 1-2 minutes, then check if the container stays running. If it crashes, debug with docker logs pg84-temp to fix any issues with the old data—you can’t upgrade a corrupted database. Once validated, clean up the temp container:

docker stop pg84-temp && docker rm pg84-temp

Step 2: Set up shared directories for the upgrade #

You’ll need a space where both old and new data can be accessed by the upgrade process. Create local directories (or use Docker volumes) and fix permissions for the postgres user:

mkdir -p ~/pg-upgrade/old-data ~/pg-upgrade/new-data
cp -r /path/to/your/old-8.4-data/* ~/pg-upgrade/old-data/
# 999 is the UID/GID of the postgres user in official PostgreSQL images
sudo chown -R 999:999 ~/pg-upgrade/old-data ~/pg-upgrade/new-data

Step 3: Run the upgrade with a dual-version container #

The catch: PostgreSQL’s pg_upgrade needs both old (8.4) and new (10.4) binaries. The official 10.4 image doesn’t include 8.4 tools, so we’ll use a Debian-based container that installs both versions:

docker run --rm -it \
  -v ~/pg-upgrade/old-data:/old-data \
  -v ~/pg-upgrade/new-data:/new-data \
  debian:stretch \
  bash -c "
    # Add PostgreSQL repo and install both versions
    echo 'deb http://apt.postgresql.org/pub/repos/apt/ stretch-pgdg main' > /etc/apt/sources.list.d/pgdg.list
    wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add -
    apt-get update && apt-get install -y postgresql-8.4 postgresql-10
    # Switch to postgres user to avoid permission issues
    su - postgres
    # Initialize empty 10.4 cluster
    initdb -D /new-data
    # Run the actual upgrade
    pg_upgrade \
      --old-datadir=/old-data \
      --new-datadir=/new-data \
      --old-bindir=/usr/lib/postgresql/8.4/bin \
      --new-bindir=/usr/lib/postgresql/10/bin
  "

Watch the output for errors—if everything goes well, you’ll see a success message along with post-upgrade scripts.

Step 4: Verify the upgraded database #

Test the new data directory with your PostgreSQL 10.4 Docker image:

docker run -d --name pg10-upgraded \
  -v ~/pg-upgrade/new-data:/var/lib/postgresql/data \
  -p 5432:5432 \
  postgres:10.4

Connect to the database to confirm your data is intact:

# From your local machine (if psql is installed)
psql -h localhost -U postgres
# Or from inside the container
docker exec -it pg10-upgraded psql -U postgres

Run a few queries to check tables, data, and schema match your old database. Don’t forget to run the analyze_new_cluster.sh script generated during upgrade to refresh database statistics.

Critical Tips #

• Backup first! Make a full copy of your old 8.4 data directory before starting—this is your safety net if anything goes wrong.
• Use the --link flag with pg_upgrade only if you’re confident: it saves space/time by hardlinking files, but makes rolling back to the old cluster impossible.
• Once you confirm the upgrade works, you can safely delete the old data directory and temporary files.

内容的提问来源于stack exchange，提问作者Steven P