bowenli86 commented on a change in pull request #9163: [FLINK-13086]add Chinese
documentation for catalogs
URL: https://github.com/apache/flink/pull/9163#discussion_r305536300
##########
File path: docs/dev/table/catalog.zh.md
##########
@@ -23,101 +23,102 @@ specific language governing permissions and limitations
under the License.
-->
-Catalogs provide metadata, such as names, schemas, statistics of tables, and
information about how to access data stored in a database or other external
systems. Once a catalog is registered within a `TableEnvironment`, all its
meta-objects are accessible from the Table API and SQL queries.
-
+Catalog提供元数据，例如名称，模式，表的统计信息以及有关如何访问存储在数据库或其他外部系统中的数据。
一旦目录在`TableEnvironment`中注册，就可以从Table API和SQL查询中访问其所有元对象。
* This will be replaced by the TOC
{:toc}
-Catalog Interface
+Catalog接口
-----------------
-APIs are defined in `Catalog` interface. The interface defines a set of APIs
to read and write catalog meta-objects such as database, tables, partitions,
views, and functions.
+API在`Catalog`接口中被定义。 该接口定义了一组API，用于读取和写入目录元对象，如数据库，表，分区，视图和函数。
-Catalog Meta-Objects Naming Structure
+Catalog元对象命名结构
-------------------------------------
-Flink's catalogs use a strict two-level structure, that is, catalogs contain
databases, and databases contain meta-objects. Thus, the full name of a
meta-object is always structured as `catalogName`.`databaseName`.`objectName`.
+Flink的catalog使用严格的两级结构，即catalog包含数据库，数据库包含元对象。
因此，元对象的全名总是被构造为`catalogName`.`databaseName`.`objectName`。
+
-Each `TableEnvironment` has a `CatalogManager` to manager all registered
catalogs. To ease access to meta-objects, `CatalogManager` has a concept of
current catalog and current database. By setting current catalog and current
database, users can use just the meta-object's name in their queries. This
greatly simplifies user experience.
+每个`TableEnvironment`都有一个`CatalogManager`来管理所有已注册的catalog。
为了便于访问元对象，`CatalogManager`具有当前目录和当前数据库的概念。 通过设置当前目录和当前数据库，用户可以在查询中仅使用元对象的名称。
这极大地简化了用户体验。
-For example, a previous query as
+例如，以前的查询为
```sql
select * from mycatalog.mydb.myTable;
```
-can be shortened to
+可以缩短为
```sql
select * from myTable;
```
-To querying tables in a different database under the current catalog, users
don't need to specify the catalog name. In our example, it would be
+要查询当前catalog下的其他数据库中的表，用户无需指定catalog名称。 在我们的例子中，它将是
```
select * from mydb2.myTable2
```
-`CatalogManager` always has a built-in `GenericInMemoryCatalog` named
`default_catalog`, which has a built-in default database named
`default_database`. If no other catalog and database are explicitly set, they
will be the current catalog and current database by default. All temp
meta-objects, such as those defined by `TableEnvironment#registerTable` are
registered to this catalog.
+`CatalogManager`总是有一个名为`default_catalog`的内置`GenericInMemoryCatalog`，它有一个名为`default_database`的内置默认数据库。
如果没有显式设置其他目录和数据库，则默认情况下它们将会使用当前目录和当前数据库。
所有临时元对象（例如由`TableEnvironment#registerTable`定义的对象）都将注册到此目录中。
+
-Users can set current catalog and database via
`TableEnvironment.useCatalog(...)` and `TableEnvironment.useDatabase(...)` in
Table API, or `USE CATALOG ...` and `USE DATABASE ...` in Flink SQL.
+在FLINK SQL中，用户可以通过Table
API中的`TableEnvironment.useCatalog（...）`和`TableEnvironment.useDatabase（...）`，或`USE
CATALOG ...`和`USE DATABASE ...`来设置当前目录和数据库。
-Catalog Types
+Catalog的类型
Review comment:
```suggestion
Catalog类型
```
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
[email protected]
With regards,
Apache Git Services
