# After downloading, move to your target directory
mv ~/Downloads/v11.5.x_linuxx64_server_dec.tar.gz /opt/

# Extract the archive
cd /opt
tar -xzf v11.5.x_linuxx64_server_dec.tar.gz

# List extracted contents
ls server_dec/

# Create instance owner user
sudo useradd -m -d /home/db2inst1 -g db2iadm1 db2inst1
sudo passwd db2inst1

# Create fence user
sudo groupadd db2fadm1
sudo useradd -m -d /home/db2fenc1 -g db2fadm1 db2fenc1
sudo passwd db2fenc1

# Create group for instance admin
sudo groupadd db2iadm1

# Add db2inst1 to its group
sudo usermod -g db2iadm1 db2inst1

# Run the interactive installer as root
sudo /opt/server_dec/db2setup

# Alternatively, for a command-line (non-GUI) install
sudo /opt/server_dec/db2_install -b /opt/ibm/db2/V11.5 -p SERVER -f notsamp

# Create a response file
cat > /tmp/db2_install.rsp << 'EOF'
LIC_AGREEMENT = ACCEPT
PROD = SERVER
FILE = /opt/ibm/db2/V11.5
INSTALL_TYPE = TYPICAL
INSTANCE = db2inst1
NAME = db2inst1
GROUP_NAME = db2iadm1
HOME_DIRECTORY = /home/db2inst1
PASSWORD = db2admin
AUTOSTART = YES
FENCED_USERNAME = db2fenc1
FENCED_GROUP_NAME = db2fadm1
EOF

# Run silent install
sudo /opt/server_dec/db2setup -r /tmp/db2_install.rsp

# As root, create the DB2 instance
sudo /opt/ibm/db2/V11.5/instance/db2icrt \
  -u db2fenc1 \
  db2inst1

# Switch to the instance owner
su - db2inst1

# Start the DB2 instance
db2start

# Verify the instance is running
db2 GET INSTANCE
# Output: The current database manager instance is: db2inst1

# As db2inst1, open the DB2 CLP
su - db2inst1

# Create a database with UTF-8 encoding and 32K pages
db2 CREATE DATABASE LEARNDB \
  USING CODESET UTF-8 \
  TERRITORY US \
  COLLATE USING SYSTEM \
  PAGESIZE 32768

# Connect to the database
db2 CONNECT TO LEARNDB

# Verify by querying the catalog
db2 "SELECT TABSCHEMA, TABNAME FROM SYSCAT.TABLES \
     WHERE TYPE = 'T' FETCH FIRST 10 ROWS ONLY"

# Disconnect
db2 CONNECT RESET

# Check the DB2 instance is listening on port 50000
db2 GET DBM CFG | grep SVCENAME
# Should show: SVCENAME = db2c_db2inst1 (or the port number)

# Update the service port if needed
db2 UPDATE DBM CFG USING SVCENAME 50000
db2stop
db2start

# On RHEL/CentOS, open firewall port
sudo firewall-cmd --permanent --add-port=50000/tcp
sudo firewall-cmd --reload

# On Ubuntu with ufw
sudo ufw allow 50000/tcp

Start Menu → IBM DB2 → DB2COPY1 → DB2 Command Window - Administrator

REM Verify DB2 is running
db2 GET INSTANCE
REM Output: The current database manager instance is: DB2

REM Check DB2 version
db2level
REM Output: DB21085I  This instance or install (instance name, where applicable: "DB2")
REM uses "64" bits and DB2 code release "SQL11050" with level identifier "0610010G"...

REM Start DB2 if not already running
db2start

REM Create a test database
db2 CREATE DATABASE LEARNDB USING CODESET UTF-8 TERRITORY US PAGESIZE 32768

REM Connect
db2 CONNECT TO LEARNDB

REM Check service status
sc query DB2COPY1_db2inst1

REM Start DB2 service manually
net start DB2COPY1_db2inst1

REM Stop DB2 service
net stop DB2COPY1_db2inst1

# Pull the official IBM DB2 Community Edition image
docker pull icr.io/db2_community/db2

# Run a DB2 container with a persistent volume
docker run -itd \
  --name mydb2 \
  --privileged=true \
  -p 50000:50000 \
  -e LICENSE=accept \
  -e DB2INST1_PASSWORD=Passw0rd! \
  -e DBNAME=testdb \
  -v /your/local/path/db2data:/database \
  icr.io/db2_community/db2

# Watch the startup log (DB2 takes 2-4 minutes to initialise)
docker logs -f mydb2
# Wait until you see: (*) Setup has completed.

# Open a bash shell inside the container as root
docker exec -it mydb2 bash

# Switch to the DB2 instance user inside the container
su - db2inst1

# Connect to the pre-created database
db2 CONNECT TO testdb

# Run a test query
db2 "SELECT CURRENT TIMESTAMP FROM SYSIBM.SYSDUMMY1"

# List databases
db2 LIST DATABASE DIRECTORY

// Connect to DB2 in Docker from a Java application on the host
String url = "jdbc:db2://localhost:50000/testdb";
String user = "db2inst1";
String password = "Passw0rd!";

Connection conn = DriverManager.getConnection(url, user, password);
System.out.println("Connected to DB2 in Docker: " + conn.isValid(5));

# Stop the container
docker stop mydb2

# Start it again (data persists if you used a volume)
docker start mydb2

# Remove the container (data persists if volume was used)
docker rm mydb2

# Get container IP
docker inspect mydb2 | grep IPAddress

# Enable Rosetta 2 in Docker Desktop settings:
# Settings → General → Enable Rosetta for x86/amd64 emulation on Apple Silicon

# Then pull and run the x86 DB2 image with platform flag
docker pull --platform linux/amd64 icr.io/db2_community/db2

docker run -itd \
  --platform linux/amd64 \
  --name mydb2mac \
  --privileged=true \
  -p 50000:50000 \
  -e LICENSE=accept \
  -e DB2INST1_PASSWORD=Passw0rd! \
  -e DBNAME=testdb \
  icr.io/db2_community/db2

# Check the DB2 version and build level
db2level

# Check the database manager configuration
db2 GET DBM CFG

# Check the database configuration
db2 GET DB CFG FOR LEARNDB

# List all databases
db2 LIST DATABASE DIRECTORY

# Check active connections
db2 LIST APPLICATIONS

# Run a catalog query
db2 "SELECT TABSCHEMA, TABNAME, CARD AS ROW_COUNT
     FROM SYSCAT.TABLES
     WHERE TYPE = 'T'
     ORDER BY TABSCHEMA, TABNAME
     FETCH FIRST 20 ROWS ONLY"

db2 CONNECT TO LEARNDB

# Create a schema
db2 "CREATE SCHEMA DEMO AUTHORIZATION db2inst1"

# Set the default schema for the session
db2 "SET CURRENT SCHEMA = DEMO"

# Create a test table
db2 "CREATE TABLE DEMO.EMPLOYEES (
  EMP_ID     INTEGER      NOT NULL GENERATED ALWAYS AS IDENTITY,
  FIRST_NAME VARCHAR(50)  NOT NULL,
  LAST_NAME  VARCHAR(50)  NOT NULL,
  DEPT       CHAR(4),
  SALARY     DECIMAL(12,2),
  HIRE_DATE  DATE         NOT NULL DEFAULT CURRENT DATE,
  CONSTRAINT PK_EMP PRIMARY KEY (EMP_ID)
)"

# Insert test data
db2 "INSERT INTO DEMO.EMPLOYEES (FIRST_NAME, LAST_NAME, DEPT, SALARY)
VALUES
  ('Alice',   'Smith',   'ENGR', 95000.00),
  ('Bob',     'Jones',   'MKTG', 82000.00),
  ('Charlie', 'Lee',     'ENGR', 102000.00),
  ('Diana',   'Patel',   'MGMT', 120000.00)"

# Query the data
db2 "SELECT EMP_ID, FIRST_NAME, LAST_NAME, SALARY
     FROM DEMO.EMPLOYEES
     ORDER BY SALARY DESC"

# Enable archive logging (recommended even for dev — mirrors production)
db2 UPDATE DB CFG FOR LEARNDB USING LOGARCHMETH1 LOGRETAIN

# Increase log file size for large transactions
db2 UPDATE DB CFG FOR LEARNDB USING LOGFILSIZ 8192
db2 UPDATE DB CFG FOR LEARNDB USING LOGPRIMARY 10
db2 UPDATE DB CFG FOR LEARNDB USING LOGSECOND 10

# Enable auto-resize for tablespaces
db2 UPDATE DB CFG FOR LEARNDB USING AUTO_RESIZE_ENABLED YES

# Enable self-tuning memory
db2 UPDATE DB CFG FOR LEARNDB USING SELF_TUNING_MEM ON

# Take a full backup after enabling archive logging (required)
db2 BACKUP DB LEARNDB TO /tmp/db2backup

# Reconnect
db2 CONNECT TO LEARNDB

// Connect to IBM Cloud Db2 from Java (SSL required)
String url = "jdbc:db2://your-hostname.databases.appdomain.cloud:50001/BLUDB"
           + ":sslConnection=true;";
Properties props = new Properties();
props.setProperty("user", "username");
props.setProperty("password", "password");
Connection conn = DriverManager.getConnection(url, props);

# Check the DB2 diagnostic log
tail -100 ~/sqllib/db2dump/DIAG0000/db2diag.log

# If the issue is port conflict, change the port
db2 UPDATE DBM CFG USING SVCENAME 50001
db2start

# Verify DB2 is listening on the port
netstat -tlnp | grep 50000
# or
ss -tlnp | grep 50000

# Check the service name is configured
cat /etc/services | grep db2

# If missing, add it
echo "db2c_db2inst1  50000/tcp" | sudo tee -a /etc/services
db2stop
db2start

# Reduce the database heap size
db2 UPDATE DB CFG FOR LEARNDB USING DBHEAP 5000

# Reduce the buffer pool size
db2 ALTER BUFFERPOOL IBMDEFAULTBP SIZE 500

db2stop
db2start
db2 CONNECT TO LEARNDB

# Instance management
db2start                              # Start the instance
db2stop                               # Stop the instance
db2stop force                         # Stop, disconnecting all sessions
db2 GET INSTANCE                      # Show current instance name
db2level                              # Show DB2 version

# Database management
db2 CREATE DATABASE dbname            # Create a database
db2 DROP DATABASE dbname              # Drop a database
db2 LIST DATABASE DIRECTORY           # List all catalogued databases
db2 CONNECT TO dbname                 # Connect to a database
db2 CONNECT RESET                     # Disconnect
db2 GET DB CFG FOR dbname             # View database configuration
db2 GET DBM CFG                       # View instance configuration

# Backup and recovery
db2 BACKUP DB dbname TO /path         # Full offline backup
db2 BACKUP DB dbname ONLINE TO /path  # Online backup (requires archive logging)
db2 RESTORE DB dbname FROM /path      # Restore from backup

# Monitoring
db2 LIST APPLICATIONS                 # Active connections
db2 LIST TABLESPACES SHOW DETAIL      # Tablespace usage
db2 GET HEALTH SNAPSHOT FOR DATABASE ON dbname   # Health snapshot