How imeu is associated with imcu (IM 5.5)

Upper connection IM 5.5. This chapter is IM Chapter 5 of the series Use In-Memory Expression optimization query part 5 IMEU How to communicate with IMCU Related to .

The previous section talked about creating IMEU The last step , Each one IMEU Link to its associated IMCU, This section talks about IMEU How to communicate with IMCU Related to .

IMEU How to communicate with IMCU Related to

For any line , Physical column at IMCU in , Virtual columns reside in associated columns IMEU in . IMEU It's read-only and columnar , It's like IMCU equally .

because IMEU For a particular INMEMORY Segment created IMCU Logical extension of , So by default , They inherit INMEMORY Clause and Oracle Real Applications Cluster（Oracle RAC） attribute （ Such as DISTRIBUTE and DUPLICATE）. IMEU With a IMCU Related to . However , One IMCU There may be more than one IMEU. Database will IMEU Managed as a separate structure , Make it easier to add and remove .

Be careful ：

IMEU It also contains user created IN Virtual column .

If the source data changes , The database changes during repopulation IM Derived data in expression . for example , If the transaction updates... In the table 100 A salary value , Then the work process of space management （Wnnn） Will automatically update from here 100 All... Derived from a changed value IM Expression value . Database will IMCU And its associated IMEU Refill , Instead of first refilling all IMCU, Then refill all IMEU. stay IMCU Refill period ,IMCU Can still be used to query .

To be continued .

Here are IM Content of series articles ：

In-Memory The manual : Preface （IM- Preface ）

Chapter one Oracle Database In-Memory Relevant concepts (IM-1.1)

Chapter one Oracle Database In-Memory Relevant concepts （ To continue ）(IM-1.2)

Chapter two Oracle Database In-Memory Architecture ( On ) (IM-2.1)

Chapter two In-Memory Architecture (IM-2.2)

Chapter two IM Architecture ：CPU framework ：SIMD Vector processing （IM-2.3）

The third chapter Enable and adjust IM The size of the column store （IM-3.1）

Chapter four by In-Memory Enable fill objects （IM-4.1 The first part ）

Chapter four by In-Memory Enable fill objects （IM-4.2 The second part ）

Chapter four by IM Enable and disable columns for fill objects （IM-4.3 The third part ）

Chapter four by IM Enables the placement of fill objects NO INMEMORY The table specifies INMEMORY Column properties ： Example （IM-4.4 The fourth part ）

Chapter four by IM Enable and disable tablespaces for padding objects IM Column store （IM 4.5）

Chapter four Enable and disable... For materialized views IM Column store （IM 4.6）

Chapter four by IM Enables forced filling of filled objects In-Memory object ： course （IM 4.7）

Chapter four by IM Enable fill objects to IM Column storage enabled ADO（IM 4.8）

The fifth chapter Use In-Memory Expression optimization query （IM 5.1）

IM The purpose of the expression （IM 5.2）

IM How expressions work （IM 5.3）

How to fill the database IM expression （IM 5.4）

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