AND c.message ILIKE '%#' || i.index || '%'
disappears when extract returns.
圖像來源，Dan McKenzie。Line官方版本下载对此有专业解读
Think about how you'd search a large room for a lost key. You wouldn't examine every square inch sequentially. You'd split the room into sections (by the couch, near the door, under the table) and rule out entire sections at a glance. "I didn't go near the kitchen, so skip that."
，详情可参考同城约会
Additional reporting by Emma Calder
With a thousand points, you barely notice the delay. With a million, you're doing a million distance calculations for every single query. On a phone updating the map as the user scrolls, that's untenable.。业内人士推荐夫子作为进阶阅读