dt create

# Minimal
hologres dt create -t my_dt --freshness "10 minutes" \
  -q "SELECT col1, SUM(col2) FROM src GROUP BY col1"

# With partitioning and serverless
hologres dt create -t ads_report --freshness "5 minutes" --refresh-mode auto \
  --logical-partition-key ds --partition-active-time "2 days" \
  --partition-time-format YYYY-MM-DD \
  --computing-resource serverless --serverless-cores 32 \
  -q "SELECT repo_name, COUNT(*) AS events, ds FROM src GROUP BY repo_name, ds"

# Incremental refresh
hologres dt create -t tpch_q1 --freshness "3 minutes" --refresh-mode incremental \
  -q "SELECT l_returnflag, l_linestatus, COUNT(*) FROM lineitem GROUP BY 1,2"

# Dry-run (preview SQL without executing)
hologres dt create -t my_dt --freshness "10 minutes" -q "SELECT 1" --dry-run

Key create options:

dt list / show / ddl

hologres dt list                     # List all DTs with refresh info
hologres dt show public.my_dt        # Show all properties
hologres dt ddl public.my_dt         # Show CREATE statement
hologres dt list -f table            # Table format output

dt lineage

hologres dt lineage public.my_dt     # Single table lineage
hologres dt lineage --all            # All DTs lineage
hologres dt lineage my_dt -f table   # Table format

base_table_type: r=table, v=view, m=materialized view, f=foreign table, d=Dynamic Table.

dt storage / state-size

hologres dt storage public.my_dt      # Storage breakdown
hologres dt state-size public.my_dt   # State table size (incremental DTs)

dt refresh

hologres dt refresh my_dt
hologres dt refresh my_dt --overwrite --partition "ds = '2025-04-01'" --mode full
hologres dt refresh my_dt --dry-run

dt alter

hologres dt alter my_dt --freshness "30 minutes"
hologres dt alter my_dt --no-auto-refresh
hologres dt alter my_dt --refresh-mode full --computing-resource serverless
hologres dt alter my_dt --refresh-guc timezone=GMT-8:00 --dry-run

dt drop

hologres dt drop my_dt               # Dry-run by default (safety)
hologres dt drop my_dt --confirm     # Actually drop
hologres dt drop my_dt --if-exists --confirm

dt convert (V3.0 → V3.1)

hologres dt convert my_old_dt          # Convert single table
hologres dt convert --all              # Convert all V3.0 tables
hologres dt convert my_old_dt --dry-run

Output Formats

Partition Management

# List partitions
hologres partition list -t public.logs

# Drop a partition
hologres partition drop -t my_table --partition "2025-04-01" --confirm

# Alter partition properties
hologres partition alter -t public.logs --partition "ds=2025-03-16" --set "keep_alive=TRUE"
hologres partition alter -t my_table --partition "ds=2025-03-16" --set "keep_alive=TRUE" --set "storage_mode=hot" --dry-run

Output Formats

hologres -f json schema tables    # JSON (default)
hologres -f table schema tables   # Human-readable table
hologres -f csv schema tables     # CSV
hologres -f jsonl schema tables   # JSON Lines

Response Structure

// Success
{"ok": true, "data": {"rows": [...], "count": 10}}

// Error
{"ok": false, "error": {"code": "ERROR_CODE", "message": "..."}}

Safety Features

0. Default Session GUC Protection

All connections automatically set safety GUCs upon creation:

• SET hg_experimental_enable_adaptive_execution = on — Enables adaptive execution to prevent OOM
• SET hg_computing_resource = 'serverless' — Routes queries to the serverless computing pool

These are applied transparently at the connection layer; no user action needed.

1. Row Limit Protection

Queries without LIMIT returning >100 rows fail with LIMIT_REQUIRED.

# Will fail if >100 rows
hologres sql run "SELECT * FROM large_table"

# Fix: add LIMIT
hologres sql run "SELECT * FROM large_table LIMIT 50"

# Or disable check
hologres sql run --no-limit-check "SELECT * FROM large_table"

2. Write Protection

Write operations (INSERT, UPDATE, DELETE, DROP, CREATE, ALTER, TRUNCATE, GRANT, REVOKE) require --write flag.

hologres sql run --write "INSERT INTO logs VALUES (1, 'test')"

3. Dangerous Write Blocking

DELETE/UPDATE without WHERE clause are blocked.

# Blocked
hologres sql run --write "DELETE FROM users"

# Must have WHERE
hologres sql run --write "DELETE FROM users WHERE status='inactive'"

Error Codes

Sensitive Data Masking

Auto-masks by column name pattern:

• phone/mobile/tel → 138**5678
• email → j*@example.com
• password/secret/token → **

Disable: hologres sql run --no-mask "SELECT * FROM users LIMIT 10"

References

Best Practices

1. Always use LIMIT for large result sets
2. Use --dry-run to preview DT SQL before executing
3. Use --confirm explicitly for destructive operations (table drop, table truncate, dt drop)
4. Include WHERE clause in DELETE/UPDATE
5. Use JSON output for automation/scripting
6. Check hologres status before batch operations
7. Use hologres dt lineage to understand DT dependencies before altering

SQL Tracking

Set HOLOGRES_SKILL environment variable before calling CLI to tag queries with skill origin:

export HOLOGRES_SKILL=hologres-query-optimizer
hologres sql run "SELECT * FROM orders LIMIT 10"

Queries will appear in hg_query_log with application_name = "hologres-cli/hologres-query-optimizer".

This enables per-skill SQL statistics on the Hologres server:

SELECT
  split_part(application_name, '/', 2) AS skill,
  COUNT(*) AS query_count,
  AVG(duration) AS avg_duration_ms
FROM hologres.hg_query_log
WHERE query_start > now() - interval '1 hour'
  AND application_name LIKE 'hologres-cli/%'
GROUP BY 1
ORDER BY 2 DESC;