qidaye commented on code in PR #16735:
URL: https://github.com/apache/doris/pull/16735#discussion_r1108173773
##########
docs/en/docs/data-table/best-practice.md:
##########
@@ -180,62 +180,4 @@ Users can modify the Schema of an existing table through
the Schema Change opera
- Adding or modifying Bloom Filter
- Adding or removing bitmap index
-For details, please refer to [Schema Change](
-
-## Row Store format
-We support row format for olap table to reduce point lookup io cost, but to
enable this format you need to spend more disk space for row format
store.Currently we store row in an extra column called `row column` for
simplicity.Row store is disabled by default, users can enable it by adding the
following property when create table
-```
-"store_row_column" = "true"
-```
-
-## Accelerate point query for merge-on-write model
-As we provided row store format , we could use such store format to speed up
point query performance for merge-on-write model.For point query on primary
keys when `enable_unique_key_merge_on_write` enabled, planner will optimize
such query and execute in a short path in a light weight RPC interface.Bellow
is an example of point query with row store on merge-on-write model:
-```
-CREATE TABLE `tbl_point_query` (
- `key` int(11) NULL,
- `v1` decimal(27, 9) NULL,
- `v2` varchar(30) NULL,
- `v3` varchar(30) NULL,
- `v4` date NULL,
- `v5` datetime NULL,
- `v6` float NULL,
- `v7` datev2 NULL
-) ENGINE=OLAP
-UNIQUE KEY(key)
-COMMENT 'OLAP'
-DISTRIBUTED BY HASH(key) BUCKETS 1
-PROPERTIES (
-"replication_allocation" = "tag.location.default: 1",
-"enable_unique_key_merge_on_write" = "true",
-"light_schema_change" = "true",
-"store_row_column" = "true"
-);
-```
-[NOTE]
-1. `enable_unique_key_merge_on_write` should be enabled, since we need primary
key for quick point lookup in storage engine
-2. when condition only contains primary key like `select * from
tbl_point_query where key = 123`, such query will go through the short fast path
-3. `light_schema_change` should also been enabled since we rely `column unique
id` of each columns when doing point query.
-
-### Using `PreparedStatement`
-In order to reduce CPU cost for parsing query SQL and SQL expressions, we
provide `PreparedStatement` feature in FE fully compatible with mysql protocol
(currently only support point queries like above mentioned).Enable it will pre
caculate PreparedStatement SQL and expresions and caches it in a session level
memory buffer and will be reused later on.We could improve 4x+ performance by
using `PreparedStatement` when CPU became hotspot doing such queries.Bellow is
an JDBC example of using `PreparedStatement`.
-
-1. Setup JDBC url and enable server side prepared statement
-```
-url = jdbc:mysql://127.0.0.1:9137/ycsb?useServerPrepStmts=true
-``
-
-2. Using `PreparedStatement`
-```java
-// use `?` for placement holders, readStatement should be reused
-PreparedStatement readStatement = conn.prepareStatement("select * from
tbl_point_query where key = ?");
-...
-readStatement.setInt(1234);
-ResultSet resultSet = readStatement.executeQuery();
-...
-readStatement.setInt(1235);
-resultSet = readStatement.executeQuery();
-...
-```
-
-
-
+For details, please refer to [Schema Change](
Review Comment:
Please add relative path.
--
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.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
