OceanBase implements code generator to translate the reasonable execution prepare into reentrant Bodily execution approach. Operate finished by code generator contains translating the sensible operators into Actual physical operators, converting the infix expression into suffix expression, leveraging the syntactic facts to create logical facts, eliminating the redundant facts construction, etc. OceanBase caches these options to stop re-compiling them in upcoming.
(three) Alternate Compaction: When just one ObServer is about to compact a single partition, queries around the merged partition is going to be sent to ObServers in other Zones storing replicas of a similar partition.
The most quantity of columns in The interior illustration of the desk are unable to exceed 1022 following column addition with the INSTANT algorithm. The error information is:
TRUNCATE is DDL not DML. That may not look sensible right up until you stop and examine how it's carried out as well as permissions necessary. It really is basically syntactic shorthand for any DROP accompanied by a Build utilizing the same initial schema.
general public DDL(DBObject obj) Results in a fresh DDL object which is able to include statements to Oracle迁移MySQL carry out actions regarding the offered item.
@RichardSmith really recognize your remark, clarifying it anybody who reads this reply. And soon after I look at this remark, it seems very rational that TRUNCATE is DDL
OceanBase adopts MVCC to complete concurrency control. In the event the operation requires one partition or multiple partitions on solitary server node, it is going to browse the snapshot of that server node. If your Procedure requires partitions on many server nodes, it executes dispersed snapshot study.
Renaming a desk could be performed immediately or in place. MySQL renames information that correspond to your desk tbl_name
For index vary, as OceanBase splits desk into partitions, it supports community indexing for community partitions and world-wide indexing for global partitions.
OceanBase employs physiological logging to information many of the modification. Physiological targets about the modification on Each and every solitary page with out specifying the in depth data Business within the web site. OceanBase works by using Paxos consensus algorithm to synchronize log replicas on various server nodes.
OceanBase also supports secondary index. It brings together index keys and desk Main crucial for secondary index.
OceanBase uses column compression. It implements a number of encoding algorithms and it quickly chooses 数据库国产化迁移 the best suited 1 for each column. It adopts column compression to leverage information similarity, for example exact same details style, similar value vary, and many others.
By making use of this constructor around the empty Variation, error reporting on any statements executed in opposition to the database will be able to contain the details of the item the assertion was related to.
OceanBase supports standard SQL question interface, however there are slight differences in OceanBase implementation.