Unverified50% confidenceFactExact time
PostgreSQL默认将NULL视为最大值，升序排序中排在末尾，降序中排在开头
1
Sources
50%
Confidence
Long-term
Relevance
9/12/2026
First Seen
Sources
Related Entities
Related Claims
Unverified在PostgreSQL中，SELECT NULL = NULL 返回NULL而不是TRUE74% similarUnverifiedPostgreSQL的聚合函数会忽略NULL值：COUNT(*)统计所有行，COUNT(val)、SUM、AVG忽略NULL值74% similarUnverified对于 PostgreSQL，分区总数建议不超过1000个72% similarUnverifiedPostgreSQL 扩展在查询规划器层面与内核完全平等，优化器能够感知并利用扩展索引的统计信息生成执行计划67% similarUnverifiedDECIMAL与NUMERIC在标准SQL中语义等价，均通过十进制精确存储数字，避免FLOAT/DOUBLE二进制浮点表示的舍入误差66% similar
Cite This Claim
Stable URI
https://kongchang.com/claim/910657API
curl https://kongchang.com/api/v1/knowledge/claims/910657MCP
get_claim(id=910657)