access” is possible because of the ordering. There are also structure pages (called “nonleaf”) that help guide the DBMS in understanding on what index pages certain values are. The DBMS will traverse these structure pages to get to the “leaf” pages, which is where the index entries ...
However, size and matter of time result when this graph summary is generated. The various structure index has been proposed until now to solve this problem. While decreasing the size of the index that became the problem of the structure index that has been proposed until now in this research...
对象类型对象操作类型 数据库模式 模式 CREATE SCHEMA 基本表 CREATE SCHEMA,ALTER TABLE 视图 CREATE VIEW 索引 CREATE INDEX 数据 基本表和视图 SELECT,INSERT,UPDATE,DELETE,REFERENCES,ALL PRIVILEGES 属性列 SELECT,INSERT,UPDATE,REFERENCES,ALL PRIVILEGES
Note that performance might be improved by updating stats on oracle: BEGIN DBMS_STATS.GATHER_SCHEMA_STATS DBMS_STATS.GATHER_DATABASE_STATS DBMS_STATS.GATHER_DICTIONARY_STATS END; Generate a migration template The two options --project_base and --init_project when used indicate to ora2pg that ...
DEL_LF_ROWS_LEN(total length of all deleted rows in the index) LF_ROWS_LEN (sum of the lengths of all the leaf rows) 如果结果大于20%, 那你的Index就可以被rebuild了。 validate structure有二中模式: online, offline, 默认是offline模式。以offline模式分析时, 会對表加一个4级別的锁(表共享),对...
Most of these cache-conscious indexes are variants of conventional B+-trees, and have better cache performance than B+-trees. In this paper, we develop a novel J + -tree index, inspired by the Judy structure which is an associative array data structure, and propose a more cache-optimized ...
In Section “Deconstructing database storage”, we analyze the interesting storage layout parameter trade-offs and explain how these parameters and some user actions can be discovered within a DBMS. Section “Experiments” reports experimental analysis results for a variety of different databases and ...
- 《Systems & Computers in Japan》 被引量: 28发表: 1998年 Two-dimensional S-tree: an index structure for content-based retrieval of images An important feature to be considered in the design of multimedia DBMSs is content-based retrieval of images. Most work in this area has focused on ...
A method for transforming multi-dimensional data points into 1-dimensional values which are stored in a 1-dimensional index structure is disclosed. The data space is divided into a first plurality of pyramids each having a center point of the data space as a top and a (d-1) dimensional sur...
本文的中心议题是多媒体对象特征的提取与索引,其中,在特征的提取方面概述了当前科技界在这个领域取得的成果;在特征的索引方面,结合已有的多维索引结构树,给出了一个适合MMDBMS的数据结构MIX-TREE。更多例句>> 2) high-dimensional index structure 高维索引结构 1. In this paper,the video stream is segmented in...