Shell & CLI

Review the Oracle environment variables and client context used by a shell session.

printf 'ORACLE_SID=%s\nORACLE_HOME=%s\nPATH=%s\n' "$ORACLE_SID" "$ORACLE_HOME" "$PATH"

Confirm the instance name and status from a command-line SQL session.

sqlplus -s / as sysdba <<'SQL'
SET PAGESIZE 0 FEEDBACK OFF VERIFY OFF HEADING OFF
SELECT instance_name || ' ' || status
FROM v$instance;
EXIT
SQL

Review filesystem capacity before database files or backups consume available space.

df -h
printf '\nFilesystem usage above 80%%:\n'
df -P | awk 'NR > 1 && $5+0 >= 80 {print}'

Review Oracle-related processes from the operating system when investigating instance activity.

ps -ef | grep '[o]ra_' | sort

Capture command output to a timestamped log for repeatable operational evidence.

LOG_DIR=/tmp/oracle_checks
mkdir -p "$LOG_DIR"
LOG_FILE="$LOG_DIR/check_$(date +%Y%m%d_%H%M%S).log"

{
  date
  hostname
  id
  df -h
} | tee "$LOG_FILE" 

Use a small shell function to standardize a frequently repeated database check.

check_instance() {
  sqlplus -s / as sysdba <<'SQL'
SET PAGESIZE 0 FEEDBACK OFF HEADING OFF
SELECT instance_name || ' ' || status
FROM v$instance;
EXIT
SQL
}

check_instance