explorer-monorepo/docs/BLOCKSCOUT_SCHEMA_MISMATCH_FIX.md

Fix Blockscout Schema/Connection Mismatch

Problem

The migrations_status table exists when checked from postgres, but Blockscout can't see it and crashes with:

ERROR 42P01 (undefined_table) relation "migrations_status" does not exist

Root Cause

This typically indicates:

1. Schema mismatch: Table exists in a different schema than Blockscout is searching
2. Database mismatch: Blockscout connecting to different database
3. Search path issue: PostgreSQL search_path doesn't include the schema
4. Connection string issue: DATABASE_URL points to wrong database/schema

Diagnosis Commands

Run these to identify the issue:

# From VMID 5000

# 1. Check what schema the table is in
docker exec blockscout-postgres psql -U blockscout -d blockscout -c "
SELECT table_schema, table_name 
FROM information_schema.tables 
WHERE table_name = 'migrations_status';
"

# 2. Check current search_path
docker exec blockscout-postgres psql -U blockscout -d blockscout -c "SHOW search_path;"

# 3. Check Blockscout DATABASE_URL
BLOCKSCOUT_CONTAINER=$(docker ps -a | grep blockscout | grep -v postgres | awk '{print $1}' | head -1)
docker inspect --format='{{range .Config.Env}}{{println .}}{{end}}' $BLOCKSCOUT_CONTAINER | grep DATABASE_URL

# 4. Test table access with explicit schema
docker exec blockscout-postgres psql -U blockscout -d blockscout -c "
SELECT COUNT(*) FROM public.migrations_status;
"

Solutions

Solution 1: Fix Search Path

If table is in public schema but search_path doesn't include it:

docker exec blockscout-postgres psql -U blockscout -d blockscout << 'SQL'
ALTER DATABASE blockscout SET search_path = public, "$user";
\c blockscout
SELECT set_config('search_path', 'public', false);
SQL

Solution 2: Verify DATABASE_URL

Check Blockscout's DATABASE_URL matches the actual database:

# Check what Blockscout is using
BLOCKSCOUT_CONTAINER=$(docker ps -a | grep blockscout | grep -v postgres | awk '{print $1}' | head -1)
docker inspect --format='{{range .Config.Env}}{{println .}}{{end}}' $BLOCKSCOUT_CONTAINER | grep DATABASE_URL

# Should be: postgresql://blockscout:blockscout@postgres:5432/blockscout
# If different, update docker-compose.yml

Solution 3: Recreate migrations_status in Correct Schema

If table is in wrong schema, recreate it:

# Drop and recreate in public schema
docker exec blockscout-postgres psql -U blockscout -d blockscout << 'SQL'
-- Drop if exists in wrong schema
DROP TABLE IF EXISTS migrations_status CASCADE;

-- Recreate in public schema (migrations will do this)
-- Or run migrations again
SQL

# Then run migrations
BLOCKSCOUT_CONTAINER=$(docker ps -a | grep blockscout | grep -v postgres | awk '{print $1}' | head -1)
docker start $BLOCKSCOUT_CONTAINER
sleep 10
docker exec -it $BLOCKSCOUT_CONTAINER bin/blockscout eval "Explorer.Release.migrate()"

Solution 4: Check for Multiple Databases

Verify Blockscout is connecting to the correct database:

# List all databases
docker exec blockscout-postgres psql -U blockscout -d blockscout -c "\l"

# Check which database has the table
docker exec blockscout-postgres psql -U blockscout -d postgres -c "
SELECT datname FROM pg_database;
"

# For each database, check if migrations_status exists
for db in blockscout postgres; do
  echo "Checking database: $db"
  docker exec blockscout-postgres psql -U blockscout -d $db -c "
    SELECT CASE WHEN EXISTS (
      SELECT 1 FROM information_schema.tables 
      WHERE table_name = 'migrations_status'
    ) THEN '✅ EXISTS' ELSE '❌ MISSING' END;
  "
done

Most Likely Fix

The table exists but Blockscout can't see it due to schema search path. Try:

# From VMID 5000

# 1. Ensure search_path includes public
docker exec blockscout-postgres psql -U blockscout -d blockscout -c "
ALTER DATABASE blockscout SET search_path = public;
"

# 2. Verify table is accessible
docker exec blockscout-postgres psql -U blockscout -d blockscout -c "
SET search_path = public;
SELECT COUNT(*) FROM migrations_status;
"

# 3. Restart Blockscout
BLOCKSCOUT_CONTAINER=$(docker ps -a | grep blockscout | grep -v postgres | awk '{print $1}' | head -1)
docker restart $BLOCKSCOUT_CONTAINER

Automated Diagnosis

Run the diagnosis script:

# From Proxmox host
cd /home/intlc/projects/proxmox/explorer-monorepo
./scripts/diagnose-blockscout-schema-issue.sh

This will identify:

• What schema the table is in
• What search_path is configured
• What DATABASE_URL Blockscout is using
• Whether Blockscout can actually see the table