Using MOT（1）
Tags: opengauss
Published: 2023-04-17 10:44:34

This chapter describes how to deploy, use and manage openGauss MOT. Using MOT tables is quite simple. The syntax of all MOT commands is the same as for openGauss disk‑based tables. Only the create and drop table statements in MOT differ from the statements for disk-based tables in openGauss. You may refer to this chapter in order to learn how to get started, how to convert a disk‑based table into an MOT table, how to use advanced MOT features, such as Native Compilation (JIT) for Queries and Stored Procedures, execution of Cross-engine Transactions, as well as MOT's limitations and coverage. MOT administration options are also described here. This chapter also describes how to perform a TPC-C benchmark.

**· Using MOT Overview**

MOT is automatically deployed as part of openGauss. You may refer to the MOT Preparation section for a description of how to estimate and plan required memory and storage resources in order to sustain your workload. The MOT Deployment section describes all the configuration settings in MOT, as well as non-mandatory options for server optimization.

Using MOT tables is quite simple. The syntax of all MOT commands is the same as for disk-based tables and includes support for most of standard PostgreSQL SQL, DDL and DML commands and features, such as Stored Procedures. Only the create and drop table statements in MOT differ from the statements for disk-based tables in openGauss. You may refer to the MOT Usage section for a description of these two simple commands, to learn how to convert a disk-based table into an MOT table, to get higher performance using Query Native Compilation and PREPARE statements and for a description of external tool support and the limitations of the MOT engine.

The MOT Administration section describes how to perform database maintenance, monitoring and analysis of logs and reported errors. Lastly, the MOT Sample TPC-C Benchmark section describes how to perform a standard TPC-C benchmark.

**·** Read the following topics to learn how to use MOT –

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/gv23em6694sncckqo31s.png)

**· MOT Preparation**
The following describes the prerequisites and the memory and storage planning to perform in order to prepare to use MOT.

**MOT Prerequisites**
The following specifies the hardware and software prerequisites for using openGauss MOT.

**Supported Hardware**
MOT can utilize state-of-the-art hardware, as well as support existing hardware platforms. Both x86 architecture and ARM by Huawei Kunpeng architecture are supported.

MOT is fully aligned with the hardware supported by the openGauss database. For more information, see the openGauss Installation Guide.

**CPU**
MOT delivers exceptional performance on many-core servers (scale-up). MOT significantly outperforms the competition in these environments and provides near-linear scaling and extremely high resource utilization.

Even so, users can already start realizing MOT's performance benefits on both low-end, mid-range and high-end servers, starting from one or two CPU sockets, as well as four and even eight CPU sockets. Very high performance and resource utilization are also expected on very high-end servers that have 16 or even 32 sockets (for such cases, we recommend contacting Huawei support).

**Memory**
MOT supports standard RAM/DRAM for its data and transaction management. All MOT tables’ data and indexes reside in-memory; therefore, the memory capacity must support the data capacity and still have space for further growth. For detailed information about memory requirements and planning, see the MOT Memory and Storage Planning__section.

**Storage IO**
MOT is a durable database and uses persistent storage (disk/SSD/NVMe drive[s]) for transaction log operations and periodic checkpoints.

We recommend using a storage device with low latency, such as SSD with a RAID-1 configuration, NVMe or any enterprise-grade storage system. When appropriate hardware is used, the database transaction processing and contention are the bottleneck, not the IO.

For detailed memory requirements and planning, see the MOT Memory and Storage Planningsection.

Supported Operating Systems

MOT is fully aligned with the operating systems supported by openGauss.

MOT supports both bare-metal and virtualized environments that run the following operating systems on a bare-metal server or virtual machine –

**·** x86 – CentOS 7.6 and EulerOS 2.0
**·** ARM – openEuler and EulerOS
**OS Optimization**
MOT does not require any special modifications or the installation of new software. However, several optional optimizations can enhance performance. You may refer to the MOT Server Optimization – x86 and MOT Server Optimization – ARM Huawei Taishan 2P/4P sections for a description of the optimizations that enable maximal performance.