大约有 5,883 项符合查询结果（耗时：0.0285秒） [XML]
Database: To delete or not to delete records
...t possible of course) an aggregation scheme, and shove that off to another table. This will keep your primary table clean of 'deleted' data, as well as keep your secondary table optimized for monitoring purposes (or whatever you had in mind).
For temporal data, see: http://talentedmonkeys.wordpress...
Non-Relational Database Design [closed]
...a stores that don't use traditional relational design or SQL (such as Hypertable, CouchDB, SimpleDB, Google App Engine datastore, Voldemort, Cassandra, SQL Data Services, etc.). They're also often referred to as "key/value stores", and at base they act like giant distributed persistent hash tables.
...
How to select multiple rows filled with constants?
Selecting constants without referring to a table is perfectly legal in an SQL statement:
15 Answers
...
Split function equivalent in T-SQL?
...to split '1,2,3,4,5,6,7,8,9,10,11,12,13,14,15...' (comma delimited) into a table or table variable.
15 Answers
...
What does android:layout_weight mean?
...specify a size ratio between multiple views. E.g. you have a MapView and a table which should show some additional information to the map. The map should use 3/4 of the screen and table should use 1/4 of the screen. Then you will set the layout_weight of the map to 3 and the layout_weight of the tab...
Should I index a bit field in SQL Server?
...k for a set of rows, SQL uses the index to find the rows more quickly than table scanning (looking at every row).
SQL has clustered and non-clustered indexes. My understanding of clustered indexes is that they group similar index values into the same page. This way when you ask for all the rows m...
The model backing the context has changed since the database was created
...eded to use the model with a hash of the schema stored in an
EdmMetadata table that is created with a database (when Code First is
the one creating the database). Existing databases won’t have the
EdmMetadata table and so won’t have the hash…and the implementation
today will throw if t...
Preventing Laravel adding multiple records to a pivot table
...in the array. This way, only the id's given in the array will exist in the table. Brilliant @Barryvdh uses an undocumented second parameter to disable that detaching, so no relationships not in the given array are deleted but only unique id's will be attached. Check out the "syncing for convienence"...
Delete sql rows where IDs do not have a match from another table
I'm trying to delete orphan entries in a mysql table.
3 Answers
3
...
Big-O summary for Java Collections Framework implementations? [closed]
...s next notes
HashSet O(1) O(1) O(h/n) h is the table capacity
LinkedHashSet O(1) O(1) O(1)
CopyOnWriteArraySet O(n) O(n) O(1)
EnumSet O(1) O(1) O(1)
TreeSet O(log n) O(log n) O(log n)
ConcurrentSkipListSet O...