temp tbl

Author: soyeric128

docs/en/sql-reference/00-sql-reference/20-system-tables/system-temp-tables.md

@@ -0,0 +1,18 @@
+---
+title: system.temporary_tables
+---
+import FunctionDescription from '@site/src/components/FunctionDescription';
+
+<FunctionDescription description="Introduced or updated: v1.2.666"/>
+
+Provides information about all existing temporary tables in the current session.
+
+```sql title='Examples:'
+SELECT * FROM system.temporary_tables;
+
+┌────────────────────────────────────────────────────┐
+│ database │   name   │       table_id      │ engine │
+├──────────┼──────────┼─────────────────────┼────────┤
+│ default  │ my_table │ 4611686018427407904 │ FUSE   │
+└────────────────────────────────────────────────────┘
+```

docs/en/sql-reference/10-sql-commands/00-ddl/01-table/10-ddl-create-table-external-location.md

@@ -1,5 +1,5 @@
 ---
-title: CREATE TABLE (external)
+title: CREATE EXTERNAL TABLE
 sidebar_position: 2
 ---
 

docs/en/sql-reference/10-sql-commands/00-ddl/01-table/10-ddl-create-table.md

@@ -22,13 +22,17 @@ Databend aims to be easy to use by design and does NOT require any of those oper
 - [CREATE TABLE](#create-table): Creates a table from scratch.
 - [CREATE TABLE ... LIKE](#create-table--like): Creates a table with the same column definitions as an existing one.
 - [CREATE TABLE ... AS](#create-table--as): Creates a table and inserts data with the results of a SELECT query.
-- [CREATE TRANSIENT TABLE](#create-transient-table): Creates a table without storing its historical data for Time Travel.
-- [CREATE TABLE ... EXTERNAL_LOCATION](#create-table--external_location): Creates a table and specifies an S3 bucket for the data storage instead of the FUSE engine.
+
+See also:
+
+- [CREATE TEMP TABLE](10-ddl-create-temp-table.md)
+- [CREATE TRANSIENT TABLE](10-ddl-create-transient-table.md)
+- [CREATE EXTERNAL TABLE](10-ddl-create-table-external-location.md)
 
 ## CREATE TABLE
 
 ```sql
-CREATE [ OR REPLACE ] [ TRANSIENT ] TABLE [ IF NOT EXISTS ] [ <database_name>. ]<table_name>
+CREATE [ OR REPLACE ] TABLE [ IF NOT EXISTS ] [ <database_name>. ]<table_name>
 (
     <column_name> <data_type> [ NOT NULL | NULL ] 
                               [ { DEFAULT <expr> } ] 
@@ -91,27 +95,6 @@ create table t_new compression='lz4' as select * from t_old;
 ```
 :::
 
-## CREATE TRANSIENT TABLE
-
-Creates a transient table. 
-
-Transient tables are used to hold transitory data that does not require a data protection or recovery mechanism. Dataebend does not hold historical data for a transient table so you will not be able to query from a previous version of the transient table with the Time Travel feature, for example, the [AT](./../../20-query-syntax/03-query-at.md) clause in the SELECT statement will not work for transient tables. Please note that you can still [drop](./20-ddl-drop-table.md) and [undrop](./21-ddl-undrop-table.md) a transient table.
-
-Transient tables help save your storage expenses because they do not need extra space for historical data compared to non-transient tables. See [example](#create-transient-table-1) for detailed explanations.
-
-:::caution
-Concurrent modifications (including write operations) on transient tables may cause data corruption, making the data unreadable. This defect is being addressed. Until fixed, please avoid concurrent modifications on transient tables.
-:::
-
-Syntax:
-```sql
-CREATE TRANSIENT TABLE ...
-```
-
-## CREATE TABLE ... EXTERNAL_LOCATION
-
-See [CREATE TABLE(EXTERNAL_LOCATION)](./10-ddl-create-table-external-location.md).
-
 ## Column Nullable
 
 By default, **all columns are nullable(NULL)** in Databend. If you need a column that does not allow NULL values, use the NOT NULL constraint. For more information, see [NULL Values and NOT NULL Constraint](../../../00-sql-reference/10-data-types/index.md).
@@ -327,32 +310,6 @@ SELECT * FROM books_backup;
 +----+----------------+---------+
 ```
 
-### Create Transient Table
-
-Create a transient table (temporary table) that automatically deletes data after a specified period of time:
-
-```sql
--- Create a transient table
-CREATE TRANSIENT TABLE visits (
-  visitor_id BIGINT
-);
-
--- Insert values
-INSERT INTO visits VALUES(1);
-INSERT INTO visits VALUES(2);
-INSERT INTO visits VALUES(3);
-
--- Check the inserted data
-SELECT * FROM visits;
-+-----------+
-| visitor_id |
-+-----------+
-|         1 |
-|         2 |
-|         3 |
-+-----------+
-```
-
 ### Create Table ... Column As STORED | VIRTUAL
 
 The following example demonstrates a table with a stored computed column that automatically recalculates based on updates to the "price" or "quantity" columns:

docs/en/sql-reference/10-sql-commands/00-ddl/01-table/10-ddl-create-temp-table.md

@@ -0,0 +1,85 @@
+---
+title: CREATE TEMP TABLE
+sidebar_position: 1
+---
+import FunctionDescription from '@site/src/components/FunctionDescription';
+
+<FunctionDescription description="Introduced or updated: v1.2.666"/>
+
+Creates a temporary table that is automatically dropped at the end of the session.
+
+- A temporary table is visible only within the session that created it and is automatically dropped, with all data vacuumed, when the session ends.
+- To show the existing temporary tables in the session, query the [system.temporary_tables](../../../00-sql-reference/20-system-tables/system-temp-tables.md) system table. See [Example-1](#example-1).
+- A temporary table with the same name as a normal table takes precedence, hiding the normal table until dropped. See [Example-2](#example-2).
+- No privileges are required to create or operate on a temporary table.
+- Databend supports creating temporary tables with both the [Fuse Engine](../../../00-sql-reference/30-table-engines/00-fuse.md) and [Memory Engine](../../../00-sql-reference/30-table-engines/01-memory.md).
+- To create temporary tables using BendSQL, ensure you are using the latest version of BendSQL.
+
+## Syntax
+
+```sql
+CREATE [ OR REPLACE ] { TEMPORARY | TEMP } TABLE 
+       [ IF NOT EXISTS ] 
+       [ <database_name>. ]<table_name>
+       ...
+```
+
+The omitted parts follow the syntax of [CREATE TABLE](10-ddl-create-table.md).
+
+## Examples
+
+### Example-1
+
+This example demonstrates how to create a temporary table and verify its existence by querying the [system.temporary_tables](../../../00-sql-reference/20-system-tables/system-temp-tables.md) system table:
+
+```sql
+CREATE TEMP TABLE my_table (id INT, description STRING);
+
+SELECT * FROM system.temporary_tables;
+
+┌────────────────────────────────────────────────────┐
+│ database │   name   │       table_id      │ engine │
+├──────────┼──────────┼─────────────────────┼────────┤
+│ default  │ my_table │ 4611686018427407904 │ FUSE   │
+└────────────────────────────────────────────────────┘
+```
+
+### Example-2
+
+This example demonstrates how a temporary table with the same name as a normal table takes precedence. When both tables exist, operations target the temporary table, effectively hiding the normal table. Once the temporary table is dropped, the normal table becomes accessible again:
+
+```sql
+-- Create a normal table
+CREATE TABLE my_table (id INT, name STRING);
+
+-- Insert data into the normal table
+INSERT INTO my_table VALUES (1, 'Alice'), (2, 'Bob');
+
+-- Create a temporary table with the same name
+CREATE TEMP TABLE my_table (id INT, description STRING);
+
+-- Insert data into the temporary table
+INSERT INTO my_table VALUES (1, 'Temp Data');
+
+-- Query the table: This will access the temporary table, hiding the normal table
+SELECT * FROM my_table;
+
+┌────────────────────────────────────┐
+│        id       │    description   │
+├─────────────────┼──────────────────┤
+│               1 │ Temp Data        │
+└────────────────────────────────────┘
+
+-- Drop the temporary table
+DROP TABLE my_table;
+
+-- Query the table again: Now the normal table is accessible
+SELECT * FROM my_table;
+
+┌────────────────────────────────────┐
+│        id       │       name       │
+├─────────────────┼──────────────────┤
+│               1 │ Alice            │
+│               2 │ Bob              │
+└────────────────────────────────────┘
+```

docs/en/sql-reference/10-sql-commands/00-ddl/01-table/10-ddl-create-transient-table.md

@@ -0,0 +1,33 @@
+---
+title: CREATE TRANSIENT TABLE
+sidebar_position: 1
+---
+
+Creates a table without storing its historical data for Time Travel.
+
+Transient tables are used to hold transitory data that does not require a data protection or recovery mechanism. Dataebend does not hold historical data for a transient table so you will not be able to query from a previous version of the transient table with the Time Travel feature, for example, the [AT](./../../20-query-syntax/03-query-at.md) clause in the SELECT statement will not work for transient tables. Please note that you can still [drop](./20-ddl-drop-table.md) and [undrop](./21-ddl-undrop-table.md) a transient table.
+
+:::caution
+Concurrent modifications (including write operations) on transient tables may cause data corruption, making the data unreadable. This defect is being addressed. Until fixed, please avoid concurrent modifications on transient tables.
+:::
+
+## Syntax
+
+```sql
+CREATE [ OR REPLACE ] TRANSIENT TABLE 
+       [ IF NOT EXISTS ] 
+       [ <database_name>. ]<table_name>
+       ...
+```
+
+The omitted parts follow the syntax of [CREATE TABLE](10-ddl-create-table.md).
+
+## Examples
+
+This examples creates a transient table named `visits`:
+
+```sql
+CREATE TRANSIENT TABLE visits (
+  visitor_id BIGINT
+);
+```