1. Blocking: … 2. Deadlock: … 3. What will cause deadlock in Oracle? It may happen when you try to delete a row in the parent table of which the child table has no indexes on foreign keys. Because in this case the child table will be locked as whole and it increase the …
Notes on ‘Expert Oracle’ — No.6.2: Locking — Blocking, Deadlock & Escalation Read More »
1. Server Process a.Dedicated Server: one TCP/IP connection, one server process b.Shared Server: Serveral tcp/ip connections => one dispatcher => A pool of processes 2.Connection V.S. Session In terms of Domain Logic, the two are not ‘associated’ with each other, they only ‘depend’ each other. a. A connection is physical network …
Notes on ‘Expert Oracle’ — No.5.1: Oracle Processes — Server Processes Read More »
I don’t care about it for now. Let’s create a placeholder here.
1. As programmers, you should know the fundmental details of the database, especially when concurrency and performance is concerned. 2.Don’t stick to "database portability." a. You are not going to need it. b. It’s basically impossible since databases are so different from each other, concurrency strategy for example. 3.Don’t hesitate to make use …
Notes on ‘Expert Oracle’ — No.1: Programmers should know about Oracle Read More »
1. Database and Instance Database: Static Contents in Disks Instance: Processes/Threads and Memory running on a Database A Database can only be opened by a single instance. An instance can only open a single Database. And it dies when it cloese the Database. 2. SGA: A shared memory area by all …
Notes on ‘Expert Oracle’ — No.2: Abstract of the Arch Read More »
As a programmer, I don’t I should know about this for now. So, let’s just create a placeholder here.
1. SGA & PGA a. SGA: Shared Area for all the processes/threads b. PGA: The area for a single process/thread SGA ∩ PGA == Ø 2. UGA: The area for the user a. UGA ⊆ SGA if "Shared Server" is used. b. UGA ⊆ PGA if "Dedicated Server" is used. …
比如说， 如果要看 select * from people where id= ”的测试计划， oracle会告诉你它使用了全表扫描，即使id这个字段上有索引。 而这样就不会全表扫描了： select * from people where id= ‘234’
rrr ttt
Expert One-on-One Oracle 中文版叫 Oracle专家高级编程