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Posted to commits@iotdb.apache.org by qi...@apache.org on 2020/04/03 04:16:13 UTC
[incubator-iotdb] branch update_tsfile_format created (now 604ef96)
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at 604ef96 add tsfile new format figure
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new 604ef96 add tsfile new format figure
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[incubator-iotdb] 01/01: add tsfile new format figure
Posted by qi...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
qiaojialin pushed a commit to branch update_tsfile_format
in repository https://gitbox.apache.org/repos/asf/incubator-iotdb.git
commit 604ef967d6eaa014dc93d48080d7f763610c6ce3
Author: qiaojialin <64...@qq.com>
AuthorDate: Fri Apr 3 12:16:50 2020 +0800
add tsfile new format figure
---
docs/SystemDesign/1-TsFile/2-Format.md | 18 ++++++++++++++++--
docs/zh/SystemDesign/1-TsFile/2-Format.md | 24 +++++++++++++++++++-----
2 files changed, 35 insertions(+), 7 deletions(-)
diff --git a/docs/SystemDesign/1-TsFile/2-Format.md b/docs/SystemDesign/1-TsFile/2-Format.md
index 5e37bc5..9a04701 100644
--- a/docs/SystemDesign/1-TsFile/2-Format.md
+++ b/docs/SystemDesign/1-TsFile/2-Format.md
@@ -66,13 +66,27 @@
Here is a graph about the TsFile structure.
-
+
+
+This TsFile contains two devices: d1, d2. Each device contains three measurements: s1, s2, s3. 6 timeseries in total, d1 is blue, d2 is purple. Each timeseries contains 2 Chunks.
+
+There are three parts of metadata
+
+* ChunkMetadata list that grouped by timeseries
+* TimeseriesMetadata that ordered by timeseries
+* TsFileMetadata
+
+Query Process：e.g., read d1.s1
+
+* deserialize TsFileMetadata，get the position and length of all TimeseriesMetadata of d1
+* deserialize all TimeseriesMetadata of d1，get the TimeseriesMetadata of d1.s1
+* according to TimeseriesMetadata of d1.s1，deserialize all ChunkMetadata of d1.s1
+* according to each ChunkMetadata of d1.s1，read its Chunk
#### 1.2.1 Magic String and Version Number
A TsFile begins with a 6-byte magic string (`TsFile`) and a 6-byte version number (`000001`).
-
#### 1.2.2 Data
The content of a TsFile file can be divided as two parts: data and metadata. There is a byte `0x02` as the marker between
diff --git a/docs/zh/SystemDesign/1-TsFile/2-Format.md b/docs/zh/SystemDesign/1-TsFile/2-Format.md
index 3db4efb..6c3eb11 100644
--- a/docs/zh/SystemDesign/1-TsFile/2-Format.md
+++ b/docs/zh/SystemDesign/1-TsFile/2-Format.md
@@ -65,16 +65,30 @@
下图是关于TsFile的结构图。
-
+
-#### 1.2.1 文件签名和版本号
+此文件包括两个设备 d1、d2，每个设备包含三个测点 s1、s2、s3，共 6 个时间序列，d1为蓝色，d2为紫色。每个时间序列包含两个 Chunk。
+
+元数据分为三部分
+
+* 按时间序列组织的 ChunkMetadata 列表
+* 按时间序列组织的 TimeseriesMetadata
+* TsFileMetadata
-TsFile 是由 6 个字节的 "Magic String" (`TsFile`) 和 6 个字节的版本号 (`000001`)组成。
+查询流程：以查 d1.s1 为例
+
+* 反序列化 TsFileMetadata，得到 d1 的所有 TimeseriesMetadata 的位置
+* 反序列化 d1 的所有 TimeseriesMetadata，并得到 d1.s1 的 TimeseriesMetadata
+* 根据 d1.s1 的 TimeseriesMetadata，反序列化其所有 ChunkMetadata
+* 根据 d1.s1 的每一个 ChunkMetadata，读取其 Chunk 数据
+
+#### 1.2.1 文件签名和版本号
+TsFile文件头由 6 个字节的 "Magic String" (`TsFile`) 和 6 个字节的版本号 (`000002`)组成。
#### 1.2.2 数据文件
-TsFile文件的内容可以划分为两个部分: 数据和元数据。数据和元数据之间是由一个字节的 `0x02` 做为分隔符。
+TsFile文件的内容可以划分为两个部分: 数据（Chunk）和元数据（XXMetadata）。数据和元数据之间是由一个字节的 `0x02` 做为分隔符。
`ChunkGroup` 存储了一个 *设备(device)* 一段时间的数据。
@@ -84,7 +98,7 @@ TsFile文件的内容可以划分为两个部分: 数据和元数据。数据和
##### Chunk
-一个 `Chunk` 存储了一个 *传感器(sensor)* 的数据。`Chunk` 是由一个字节的分隔符 `0x01`, 一个 `ChunkHeader` 和若干个 `Page` 构成。
+一个 `Chunk` 存储了一个 *测点(measurement)* 一段时间的数据，Chunk 内数据是按时间递增序存储的。`Chunk` 是由一个字节的分隔符 `0x01`, 一个 `ChunkHeader` 和若干个 `Page` 构成。
##### ChunkHeader