📄 cwp4240.htm
字号:
<!-- saved from url=(0007)http:// -->
<HTML><HEAD><META http-equiv="Content-Type" content="text/html; charset=UTF-8"><TITLE>Perst.Storage</TITLE><LINK REL=STYLESHEET HREF="../CommentReport.css" TYPE="text/css"></HEAD><BODY topmargin=0 rightmargin=0 leftmargin=0 style="background-image: url(../titletile.jpg); background-repeat:repeat-x; background-position: 0 0;" ><DIV CLASS="PageHeading">Perst.Storage Interface</DIV><DIV CLASS="Description"> Object storage
<P></DIV><IMG src="../GradLeft.jpg" width=7 height=378 alt="" border="0" style="position:absolute; left:10; top:18;z-Index:2"><IMG src="../GradTop.jpg" width=352 height=7 alt="" border="0" align="top" style="position:absolute; left:10; top:18; z-index:1"><DIV CLASS="Remarks"><SPAN CLASS="RemarkHdrX">Access: </SPAN>Public</DIV><TABLE CLASS="InfoTable" cellpadding=0 cellspacing=0><TR height=20><TD width=20> </TD><TD valign=top align=left width=9 bgcolor="#cccc66"><IMG SRC="../graycorner.jpg" align=top></TD><TD CLASS="TableLightLabel" WIDTH=206>Members</TD><TD CLASS="TableLightLabel" >Description</TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4241.HTM" TARGET="CNTFRAME">Root</A></TD><TD CLASS="TableLightDesc"> Get/set storage root. Storage can have exactly one root object.
If you need to have several root object and access them by name (as is is possible
in many other OODBMSes), you should create index and use it as root object.
Previous reference to the root object is rewritten but old root is not automatically deallocated.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4243.HTM" TARGET="CNTFRAME">Open</A></TD><TD CLASS="TableLightDesc"> Open the storage
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4244.HTM" TARGET="CNTFRAME">Open</A></TD><TD CLASS="TableLightDesc"> Open the storage with default page pool size
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4245.HTM" TARGET="CNTFRAME">Open</A></TD><TD CLASS="TableLightDesc"> Open the storage
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4246.HTM" TARGET="CNTFRAME">Open</A></TD><TD CLASS="TableLightDesc"> Open the storage with default page pool size
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4247.HTM" TARGET="CNTFRAME">Open</A></TD><TD CLASS="TableLightDesc"> Open the encrypted storage
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4248.HTM" TARGET="CNTFRAME">IsOpened</A></TD><TD CLASS="TableLightDesc">Check if database is opened
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4249.HTM" TARGET="CNTFRAME">Commit</A></TD><TD CLASS="TableLightDesc"> Commit changes done by the last transaction. Transaction is started implcitlely with forst update
opertation.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4250.HTM" TARGET="CNTFRAME">Rollback</A></TD><TD CLASS="TableLightDesc"> Rollback changes made by the last transaction
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4251.HTM" TARGET="CNTFRAME">Backup</A></TD><TD CLASS="TableLightDesc">
Backup current state of database
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4252.HTM" TARGET="CNTFRAME">CreateQuery</A></TD><TD CLASS="TableLightDesc"> Create JSQL query. JSQL is object oriented subset of SQL allowing
to specify arbitrary prdicates for selecting members of Perst collections
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4253.HTM" TARGET="CNTFRAME">CreateIndex</A></TD><TD CLASS="TableLightDesc"> Create new index
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4254.HTM" TARGET="CNTFRAME">CreateIndex</A></TD><TD CLASS="TableLightDesc"> Create new compound index.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4255.HTM" TARGET="CNTFRAME">CreateThickIndex</A></TD><TD CLASS="TableLightDesc"> Create new thick index (index with large number of duplicated keys)
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4256.HTM" TARGET="CNTFRAME">CreateFieldIndex</A></TD><TD CLASS="TableLightDesc">
Create new field index
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4257.HTM" TARGET="CNTFRAME">CreateFieldIndex</A></TD><TD CLASS="TableLightDesc">
Create new multi-field index
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4258.HTM" TARGET="CNTFRAME">CreateRandomAccessIndex</A></TD><TD CLASS="TableLightDesc"> Create new index optimized for access by element position.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4259.HTM" TARGET="CNTFRAME">CreateRandomAccessIndex</A></TD><TD CLASS="TableLightDesc"> Create new compound index optimized for access by element position.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4260.HTM" TARGET="CNTFRAME">CreateRandomAccessFieldIndex</A></TD><TD CLASS="TableLightDesc">
Create new field index optimized for access by element position.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4261.HTM" TARGET="CNTFRAME">CreateRandomAccessFieldIndex</A></TD><TD CLASS="TableLightDesc">
Create new multi-field index optimized for access by element position.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4262.HTM" TARGET="CNTFRAME">CreateBitIndex</A></TD><TD CLASS="TableLightDesc">
Create new bit index. Bit index is used to select object
with specified set of (boolean) properties.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4263.HTM" TARGET="CNTFRAME">CreateSpatialIndex</A></TD><TD CLASS="TableLightDesc">
Create new spatial index with integer coordinates
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4264.HTM" TARGET="CNTFRAME">CreateSpatialIndexR2</A></TD><TD CLASS="TableLightDesc">
Create new R2 spatial index
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4265.HTM" TARGET="CNTFRAME">CreateSortedCollection</A></TD><TD CLASS="TableLightDesc">
Create new sorted collection with specified comparator
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4266.HTM" TARGET="CNTFRAME">CreateSortedCollection</A></TD><TD CLASS="TableLightDesc">
Create new sorted collection. Members of this collections should implement
<code>System.IComparable</code> interface and make it possible to compare
collection members with each other as well as with serch key.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4267.HTM" TARGET="CNTFRAME">CreateSet</A></TD><TD CLASS="TableLightDesc">
Create new object set
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4268.HTM" TARGET="CNTFRAME">CreateLink</A></TD><TD CLASS="TableLightDesc"> Create one-to-many link.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4269.HTM" TARGET="CNTFRAME">CreateLink</A></TD><TD CLASS="TableLightDesc"> Create one-to-many link with specified initial size.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4270.HTM" TARGET="CNTFRAME">CreateScalableSet</A></TD><TD CLASS="TableLightDesc"> Create new scalable set references to persistent objects.
This container can effciently store small number of references as well
as very large number references. When number of memers is small,
Link class is used to store set members. When number of members exceed
some threshold, PersistentSet (based on B-Tree) is used instead.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4271.HTM" TARGET="CNTFRAME">CreateScalableSet</A></TD><TD CLASS="TableLightDesc"> Create new scalable set references to persistent objects.
This container can effciently store small number of references as well
as very large number references. When number of memers is small,
Link class is used to store set members. When number of members exceed
some threshold, PersistentSet (based on B-Tree) is used instead.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4272.HTM" TARGET="CNTFRAME">CreateList</A></TD><TD CLASS="TableLightDesc">
Create new peristent list. Implementation of this list is based on B-Tree so it can efficiently
handle large number of objects but in case of very small list memory overhead is too high.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4273.HTM" TARGET="CNTFRAME">CreateScalableList</A></TD><TD CLASS="TableLightDesc">
Create new scalable list of persistent objects.
This container can effciently handle small lists as well as large lists
When number of memers is small, Link class is used to store set members.
When number of members exceeds some threshold, PersistentList (based on B-Tree)
is used instead.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4274.HTM" TARGET="CNTFRAME">CreateScalableList</A></TD><TD CLASS="TableLightDesc">
Create new scalable list of persistent objects.
This container can effciently handle small lists as well as large lists
When number of memers is small, Link class is used to store set members.
When number of members exceeds some threshold, PersistentList (based on B-Tree)
is used instead.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4275.HTM" TARGET="CNTFRAME">CreateMap</A></TD><TD CLASS="TableLightDesc">
Create scalable persistent map.
This container can effciently handle both small and large number of members.
For small maps, implementation uses sorted array. For large maps - B-Tree.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4276.HTM" TARGET="CNTFRAME">CreateMap</A></TD><TD CLASS="TableLightDesc">
Create scalable persistent map.
This container can effciently handle both small and large number of members.
For small maps, implementation uses sorted array. For large maps - B-Tree.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4277.HTM" TARGET="CNTFRAME">CreateArray</A></TD><TD CLASS="TableLightDesc"> Create dynamcially extended array of reference to persistent objects.
It is inteded to be used in classes using virtual properties to
access components of persistent objects.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4278.HTM" TARGET="CNTFRAME">CreateArray</A></TD><TD CLASS="TableLightDesc"> Create dynamcially extended array of reference to persistent objects.
It is inteded to be used in classes using virtual properties to
access components of persistent objects.
<P></TD><TD width=20> </TD></TR><TR height=20><TD width=20> </TD><TD CLASS="TableLightDesc"> </TD><TD CLASS="TableLightDesc"><A HREF="CWP4279.HTM" TARGET="CNTFRAME">CreateRelation</A></TD><TD CLASS="TableLightDesc"> Create relation object. Unlike link which represent embedded relation and stored
inside owner object, this Relation object is standalone persisitent object
containing references to owner and members of the relation
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -