Release Notes
- v3.0
- v2.5
- v2.4
- v2.3
- v2.2
- v2.1
- v2.0
- v1.19

StarRocks
Introduction to StarRocks
Quick Start
Table Design
- Understand StarRocks table design
- Table types
- Data distribution
- Sort keys and prefix indexes
Data Loading
Data Unloading
Query Data Sources
- Catalog
- External tables
Query Acceleration
- Gather CBO statistics
- Materialized view
- Colocate Join
- Lateral Join
- Index
  - Bitmap indexing
  - Bloom filter indexing
- Computing the Number of Distinct Values
  - Use Bitmap for exact count distinct
  - Use HLL for approximate count distinct
Administration
- Deployment
  - Deploy StarRocks with StarGo
  - Deploy StarRocks on Kubernetes
    - Deploy StarRocks with Operator
    - Deploy StarRocks with Helm
  - Deploy CN
  - Deploy Broker
  - Deploy FE cluster with high availability
- Management
- Data Recovery
  - Data recovery
  - Restore FEs
- User Privilege and Authentication
  - User privilege
  - Authentication
- Performance Tuning
Reference
- SQL Reference
- Function Reference
  - Java UDFs
  - Window functions
  - Aggregate Functions
  - Array Functions
  - Bit Functions
  - Bitmap Functions
  - Conditional Functions
  - Cryptographic Functions
  - Date Functions
  - Geographic Functions
  - JSON Functions
    - Overview of JSON functions and operators
    - JSON operators
    - JSON constructor functions
    - JSON query and processing functions
  - Math Functions
    - abs
    - acos
    - asin
    - atan
    - atan2
    - bin
    - ceil
    - ceiling
    - conv
    - cos
    - cosh
    - cot
    - degrees
    - divide
    - e
    - exp
    - floor
    - fmod
    - greatest
    - least
    - ln
    - log
    - log2
    - log10
    - mod
    - multiply
    - negative
    - pi
    - pmod
    - positive
    - pow
    - radians
    - rand
    - round
    - sign
    - sin
    - sinh
    - sqrt
    - square
    - tan
    - tanh
    - truncate
  - String Functions
  - Pattern Matching Functions
  - Percentile Functions
  - Scalar Functions
    - hll_cardinality
  - Utility Functions
  - cast function
  - hash function
- System variables
- Error code
- System limits
FAQ
- Deploy
- Data Migration
  - Data Loading
  - Data Unloading
- SQL
- query_dump
- Other FAQs
Benchmark
- SSB Benchmark
- TPC-H Benchmark

Developers
- Contribute to StarRocks
- Code Style Guides
  - protobuf style guides
  - thrift style guides
- Use the debuginfo file for debugging
- Development Environment
- Trace Tools
  - Trace
Integration

Edit

SHOW DATABASES

Description

Views databases in your current StarRocks cluster or an external data source. Note that you can only view databases of an external data source in StarRocks 2.3 or later versions.

Syntax

SHOW DATABASES [FROM <catalog_name>]

Parameters

Parameter	Required	Description
catalog_name	No	The name of the internal catalog or an external catalog. If you do not specified the parameter or set the value of the parameter to the name of the internal catalog, which is default_catalog, you can view databases in your current StarRocks cluster. If you set the value of the parameter to the name of an external catalog, you can view databases in the corresponding external data source.

Examples

Example 1: View databases in your current StarRocks cluster.

SHOW DATABASES;

Or

SHOW DATABASES FROM default_catalog;

The output of the preceding statements is as follows.

+----------+
| Database |
+----------+
| db1      |
| db2      |
| db3      |
+----------+

Example 2: View databases in a Hive cluster by using the Hive1 external catalog.

SHOW DATABASES FROM hive1;

+-----------+
| Database  |
+-----------+
| hive_db1  |
| hive_db2  |
| hive_db3  |
+-----------+

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SHOW DATABASES