CachedUidGenerator为带缓存的实现,采用了双RingBuffer,Uid-RingBuffer用于存储Uid、Flag-RingBuffer用于存储Uid状态(是否可填充、是否可消费) 由于数组元素在内存中是连续分配的,可最大程度利用CPU cache以提升性能。但同时会带来「伪共享」FalseSharing问题,为此在Tail、Cursor指针、Flag-Rin
Snowflake教程1：关于教程说明书
While this is a positive development, the sheer volume of data generated as a result of digitalization is staggering. Snowflake is one such Cloud Data Warehouse that is helping out users manage this colossal volume of data. Snowflake Primary Key constraint, on the other hand, ensures ...
The following screenshot shows an example flow that learns a Random Forest model using a local H2O context which is then registered as UDF and used to predict the classes for a database table with previously unseen data. The prediction result is then stored in a Snowflake table. For another...
Similar to tables, the query results for external tablespersistfor 24 hours. Within this 24-hour period, the following operations invalidate and purge the query result cache for external tables: Any DDL operation that modifies the external table definition. This includes explicitly modifying the exter...
在实现上, UidGenerator通过借用未来时间来解决sequence天然存在的并发限制; 采用RingBuffer来缓存已生成的UID, 并行化UID的生产和消费, 同时对CacheLine补齐,避免了由RingBuffer带来的硬件级「伪共享」问题. 最终单机QPS可达600万。 项目地址: https://github.com/baidu/uid-generator/blob/master/README.zh_cn.md...
{//获取snowflake分布式ID//id 这个参数是没有意义的,只是为了和号段模式的接口统一,所以要传一个参数,自己随意定义一个com.sankuai.inf.leaf.common.Result r = snowflakeService.getId("id");//判断是否成功,成功返回具体的id,不成功返回错误提示if(r.getStatus() ==Status.SUCCESS) {returnResult.ok(r....
To use Arrow format, execute: -- at the session level ALTER SESSION SET DOTNET_QUERY_RESULT_FORMAT = ARROW; -- or at the user level ALTER USER SET DOTNET_QUERY_RESULT_FORMAT = ARROW; -- or at the account level ALTER ACCOUNT SET DOTNET_QUERY_RESULT_FORMAT = ARROW; The valid valu...
362-368: Use of KnownLineageMapping in _process_external_lineage_result_row The _process_external_lineage_result_row method now uses KnownLineageMapping for creating lineage mappings. This improves the consistency and clarity of the lineage data. 423-428: Added Dataset Pattern Validation in map_que...
Client type used for attempt. is_successstring Login status (success or failure). schema_namestring Name of schema associated with query result. execution_statusstring Execution status of query being reported. query_typestring Type of query performed. ...