PARENT_ID, NAME)values(,null,'中国');insertintoarea_test(ID, PARENT_ID, NAME)values(,1,'河南省');insertintoarea_test(ID, PARENT_ID, NAME)values(,1,'北京市');insertintoarea_test(ID, PARENT_ID, NAME)values(,11,'郑州市');insertintoarea_test(ID, PARENT...
I've a table with hierarchical data relationship (parent-child) contained in one table.How i can query the table and return the records sorted by its hierarchical level?To those who are familiar with Oracle, i'm looking for the same thing that 'Connect by' does....
parentcursor包含了SQL TEXT和相关的hash value,v$sqlarea中的每一行代表了一个parent cursor,根据address表示了其内存地址。 childcursor包含了SQL的metadata,即使得这个SQL可以执行的所有相关信息,如OBJECT和权限,优化器设置,执行计划等。v$sql中中 的每一行表示了一个child cursor,根据hash value和address与parent curso...
COLUMN tree FORMAT A20 WITH t1(id, parent_id, lvl) AS ( -- Anchor member. SELECT id, parent_id, 1 AS lvl FROM tab1 WHERE parent_id IS NULL UNION ALL -- Recursive member. SELECT t2.id, t2.parent_id, lvl+1 FROM tab1 t2, t1 WHERE t2.parent_id = t1.id ) SEARCH DEPTH ...
huckets 指向library chache object handle,handle 指向一个library cache object,即heap 0. 这个就是parent。 heap 0里保存了hash 值和所有child cursor 的地址。 parent cursor 和child cursor 结构是完全一样的。 当第二次执行相同的SQL 时, 因为第一次硬解析时已经生成了parent cursor和child cursor。 所以在...
Navigate backward into or out of tree control Shift+Tab Expand (if item contains children) Right Arrow Collapse (if item contains children) Left Arrow Move to parent from child (if expanded) Left Arrow Move to child from parent (if already expanded) Right Arrow Move up/down one item...
The root node is the topmost node of a tree. Child nodes report to the root node. Child nodes at the same level, which report to a common parent node, are called siblings. Leaves are details branching off from a node but not extending further down the tree hierarchy.Tree...
SqlSource SqlUpsertSettings SqlWriteBehaviorEnum SquareLinkedService SquareObjectDataset SquareSource SSISAccessCredential SSISChildPackage SsisEnvironment SsisEnvironmentReference SSISExecutionCredential SSISExecutionParameter SsisFolder SSISLogLocation SsisObjectMetadata SsisObjectMetadataListResponse ...
2 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 1 rows processed 说明:我们在这个表上启动了并行但没有起作用是因为CBO优化器使用了B-tree索引来检索的数据直接就定位到rowid(B-tree索引特点适合重复率比较低的字段),所以才发生了4个一致性读,发现使用索引效率非常高,资源代价比较小没...
A parent-key field that references the parent (if any) of each row This function can display the sub-tree descending from a row. The primary use case of this function is to display parent-child connections (hierarchy data). The following code demonstrates our PostgreSQL query: SELECT * FROM...