Why use a READ UNCOMMITTED isolation level?
stackoverflow.com
Why use a READ UNCOMMITTED isolation level?
数据库基本支持五种标准 SQL 事务级别：未提交读取、已提交读取、可重复读取、快照隔离和可序列化
#database #transaction
The advantage of using an ID is that because it has no meaning to humans, it never needs to change: the ID can remain the same, even if the information it identifies changes. Anything that is meaningful to humans may need to change sometime in the future—and if that information is duplicated, all the redundant copies need to be updated. That incurs
... See moreThey allow inconsistent values from concurrent writes to enter the system and force the client which reads the values to reconcile. The next section explains how reconciliation works.
Alex • System Design Interview - An insider's guide
A shadow database is similar to a replicated database, with one key difference: a shadow database mirrors all changes made to a primary database, but clients do not access the shadow. Unlike replicated databases, the shadow database is one-way (data flows from primary to shadow): it serves as a live data backup of the primary.
Eric Conrad, Seth Misenar, Joshua Feldman • CISSP Study Guide
There are benefits to a table-based enterprise analytic data set. First, you have a true “compute once, use many” scenario. The total system load from analytic professionals is going to be vastly reduced. This is because instead of having each person repetitiously running the same type of process to do big joins and aggregations, it’s going to be r
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