[TcaplusDB knowledge base]TcaplusDB restrictions
To save resources, improve performance, and improve system stability, database products are often limited, and TcaplusDB is no exception.
TcaplusDB supports two types of tables: the Protocol Buffers table of the Protobuf table TDR table of Tencent Data Representation. Protobuf is a descriptive language developed by Google that serializes structured data while emphasizing simplicity and performance. TDR is a cross-platform data representation language developed by Tencent, which combines the advantages of XML, binary and ORM (Object relational Mapping) and is widely used in the serialization scenarios of Tencent game data. TDR tables support generic tables and list tables. Generic tables are tables that represent attributes of elements, such as students, employers, and gamers, in the form of tables. A list is a list of records, such as a leaderboard of the game, and the emails in the game (usually the last 100 emails).
The restrictions are as follows:
| Serial number | resources | ceiling |
|---|---|---|
| 1 | Number of tables allowed in a single table group | 256 |
| 2 | Scale key (SHard key) | 1 |
| 3 | Number of Shards in a single table | 10000 |
| 4 | A single shard size | 256GB |
| 5 | A single table size | 2.56 PB |
| 6 | Generic table primary key fields | 4 |
| 7 | Generic table non-primary key fields | 128 |
| 8 | List Indicates the primary key field of the table | 3 |
| 9 | List Non-primary key fields of the table | 127 |
| 10 | List Indicates the number of records in the table | 1024 |
| 11 | Table index | 8 |
| 12 | Field length (also called attribute length) | 32B |
| 13 | Primary key field length | 1KB |
| 14 | Non-primary key field length | 256KB |
| 15 | Single record size | 1MB |
| 16 | Number of associated records with a single index | unlimited |
| 17 | Number of table groups that can be distributed in a single table (the same table can be distributed in one table group or multiple table groups) | 8 |
| 18 | Number of records returned by batch query | 1024 |
TcaplusDB is a distributed NoSQL database produced by Tencent. The storage and scheduling code is completely self-developed. It has features such as cache + ground fusion architecture, PB-level storage, millisecond delay, lossless horizontal expansion and complex data structure. At the same time, it has the characteristics of rich ecology, convenient migration, extremely low operation and maintenance cost and five nine high availability. Customers cover gaming, Internet, government, finance, manufacturing and Internet of Things and other fields.
