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Preface Memory resources are managed by the operating system, and allocation and recovery operations may perform system calls (for example, malloc algorithm, the larger memory space allocation interface is mmap, and the smaller space is not returned to the operating system after free). Frequent system calls will inevitably reduce system perform ...

Label PostgreSQL, imgsmlr, GiST, image eigenvalues, wavelet transform background Continued "PostgreSQL 11 Similar Image Search Plug-in imgsmlr Performance Test 1 - Single Table (400 million images)" Parallel invocation using partition table + dblink asynchronous interface. (It's better to support imgsmlr gist index scan directly at ...

Preface PostgreSQL is an open source object relational database management system (ORDBMS). This paper aims to introduce some basic operations of PostgreSQL (hereinafter referred to as pg) for beginners'reference and reference. It should be noted that all the following operations were performed in Ubuntu 16.04, using version 9.6 of PG. For diff ...

I. Introduction Probabilistic soft logic (PSL) is a machine learning framework for developing probabilistic models, developed jointly by the University of California, Santa Cruz and the University of Maryland. At present, its complex environment construction method and Groovy language expression have brought many difficulties to beginners like ...

Label PostgreSQL , ms sql , SQL Server background This paper introduces the simple deployment and use of MS SQL on Linux. https://docs.microsoft.com/zh-cn/sql/linux/quickstart-install-connect-red-hat?view=sql-server-2017 Later, I will briefly introduce how to migrate MS SQL to PostgreSQL. 1 environment CentOS 7.x x64 ECS 2. Environmental ...

Label PostgreSQL, citus, pgbouncer, network optimization, worker node background Network requirements between citus nodes: 1. The cn node accesses all worker nodes. oltp services are frequently accessed. 2. When data is redistributed, worker nodes visit each other. Access frequency is not high, OLAP business is common, once possible, data ex ...

Label PostgreSQL , Heap Only Tuple , HOT background PostgreSQL's current default storage engine generates a new version in the heap when updating records. The old version needs to recycle all index POINT associated with this version before it needs to recycle the old version after VACUUM is used. The KEY of the index of PG is the value of th ...