Address doc issues

- update create index doc
- Update cbdb-op-software-hardware.md
- fix a small formats in kafka doc

docs/cbdb-op-software-hardware.md

@@ -18,17 +18,13 @@ Apache Cloudberry supports deployment on both physical machines and virtual mach
 | ------- | ---- | ---- | -------- | -------------------- | -------- |
 | Coordinator  | 4 cores | 8 GB | SSD      | 10 Gbps NIC (2 preferred) | 1+       |
 | Segment | 4 cores | 8 GB | SSD      | 10 Gbps NIC (2 preferred) | 1+       |
-| ETCD    | 2 cores | 4 GB | SSD      | 10 Gbps NIC (2 preferred) | 2+       |
-| FTS     | 2 cores | 4 GB | SSD      | 10 Gbps NIC (2 preferred) | 1+       |
 
 #### For production environments
 
 | Component    | CPU    | Memory   | Disk type | Network                 | Instance count |
 | ------- | ------ | ------ | -------- | -------------------- | -------- |
 | Coordinator  | 16+ cores | 32+ GB | SSD      | 10 Gbps NIC (2 preferred) | 2+       |
 | Segment | 8+ cores  | 32+ GB | SSD      | 10 Gbps NIC (2 preferred) | 2+       |
-| ETCD    | 16+ cores | 64+ GB | SSD      | 10 Gbps NIC (2 preferred) | 3+       |
-| FTS     | 4+ cores  | 8+ GB   | SSD      | 10 Gbps NIC (2 preferred) | 3+       |
 
 Apache Cloudberry can also be deployed on public cloud platforms such as AWS, Azure, and GCP. The hardware requirements for cloud-based deployments might vary based on the instance types selected on these platforms. Refer to the specific cloud provider’s documentation for instance configurations that meet or exceed the recommended hardware specifications.
 

docs/data-loading/load-data-from-kafka-using-fdw.md

@@ -15,8 +15,7 @@ See the Kafka FDW repository for more information: [https://github.com/cloudberr
 - Create the `kafka_fdw` extension:
 
     ``` sql
-    postgres=# CREATE EXTENSION kafka_fdw;
-    CREATE EXTENSION
+    CREATE EXTENSION kafka_fdw;
     ```
 
 - Create an external server and specify Kafka's cluster address. You need to replace `localhost:9092` with your Kafka cluster address.

docs/sql-stmts/create-index.md

@@ -249,8 +249,6 @@ SELECT * FROM points WHERE box(location,location) && '(0,0),(1,1)'::box;
 
 `CREATE INDEX` is a Cloudberry Database extension to the SQL standard. There are no provisions for indexes in the SQL standard.
 
-Cloudberry Database does not support the concurrent creation of indexes (`CONCURRENTLY` keyword is not supported).
-
 ## See also
 
 [`ALTER INDEX`](/docs/sql-stmts/alter-index.md), [`DROP INDEX`](/docs/sql-stmts/drop-index.md)

docs/sql-stmts/reindex.md

@@ -52,8 +52,6 @@ Prints a progress report as each index is reindexed.
 
 ## Notes
 
-Cloudberry Database does not support concurrently recreating indexes (`CONCURRENTLY` keyword is not supported).
-
 `REINDEX` causes locking of system catalog tables, which could affect currently running queries. To avoid disrupting ongoing business operations, schedule the `REINDEX` operation during a period of low activity.
 
 `REINDEX` is similar to a drop and recreate of the index in that the index contents are rebuilt from scratch. However, the locking considerations are rather different. `REINDEX` locks out writes but not reads of the index's parent table. It also takes an `ACCESS EXCLUSIVE` lock on the specific index being processed, which will block reads that attempt to use that index. In contrast, `DROP INDEX` momentarily takes an `ACCESS EXCLUSIVE` lock on the parent table, blocking both writes and reads. The subsequent `CREATE INDEX` locks out writes but not reads; since the index is not there, no read will attempt to use it, meaning that there will be no blocking but reads may be forced into expensive sequential scans.

i18n/zh/docusaurus-plugin-content-docs/current/cbdb-op-software-hardware.md

@@ -18,17 +18,13 @@ Apache Cloudberry 支持在物理机和虚拟机上部署。以下是推荐的
 | ------- | ---- | ---- | -------- | -------------------- | -------- |
 | Coordinator  | 4 核 | 8 GB | SSD      | 万兆网卡（2 块最佳） | 1+       |
 | Segment | 4 核 | 8 GB | SSD      | 万兆网卡（2 块最佳） | 1+       |
-| ETCD    | 2 核 | 4 GB | SSD      | 万兆网卡（2 块最佳） | 2+       |
-| FTS     | 2 核 | 4 GB | SSD      | 万兆网卡（2 块最佳） | 1+       |
 
 #### 生产环境
 
 | 组件    | CPU    | 内存   | 硬盘类型 | 网络                 | 实例数量 |
 | ------- | ------ | ------ | -------- | -------------------- | -------- |
 | Coordinator  | 16 核+ | 32 GB+ | SSD      | 万兆网卡（2 块最佳） | 2+       |
 | Segment | 8 核+  | 32 GB+ | SSD      | 万兆网卡（2 块最佳） | 2+       |
-| ETCD    | 16 核+ | 64 GB+ | SSD      | 万兆网卡（2 块最佳） | 3+       |
-| FTS     | 4 核+  | 8+ GB   | SSD      | 万兆网卡（2 块最佳） | 3+       |
 
 Apache Cloudberry 还可以部署在公有云平台上，例如 AWS、Azure 和 GCP。基于这些平台上选择的实例类型，云端部署的硬件要求可能会有所不同。请参考具体云服务提供商的文档，了解符合或超出推荐硬件规格的实例配置。
 

i18n/zh/docusaurus-plugin-content-docs/current/data-loading/load-data-from-kafka-using-fdw.md

@@ -12,7 +12,7 @@ Apache Cloudberry 支持使用 Kafka FDW 来创建外部表以及导入数据。
 
 ## 基本使用
 
-- 创建插件。
+- 创建 `kafka_fdw` 扩展。
 
     ``` sql
     CREATE EXTENSION kafka_fdw;

i18n/zh/docusaurus-plugin-content-docs/current/sql-stmts/sql-stmt-create-index.md

@@ -249,8 +249,6 @@ SELECT * FROM points WHERE box(location,location) && '(0,0),(1,1)'::box;
 
 `CREATE INDEX` 是 Cloudberry Database 对 SQL 标准的扩展。SQL 标准中没有索引的规定。
 
-Cloudberry Database 不支持并发创建索引（不支持 `CONCURRENTLY` 关键字）。
-
 ## 另见
 
 [`ALTER INDEX`](https://github.com/cloudberrydb/cloudberrydb-site/blob/cbdb-doc-validation/docs/sql-stmts/alter-index.md)、[`DROP INDEX`](/i18n/zh/docusaurus-plugin-content-docs/current/sql-stmts/drop-index.md)