Maximum Table Size 32 TB Maximum Row Size 1.6 TB Maximum Field Size 1 GB Maximum Rows per Table Unlimited Maximum Columns per Table 250 - 1600 depending on column types Maximum Indexes per Table Unlimited mysql 目前只是适合 跑 web 应用,对于海量数据存储、数据仓库 不合适。 postgresql 在国内早有...
alter system set wal_buffers = 'xxx';,该命令会修改配置文件 postgresql.auto.conf。 effective_cache_size effective_cache_size 参数为 PostgreSQL 提供了一个可供操作系统和数据库使用的缓存估值(考虑了操作系统自身和其他应用之后)。 该参数只是一个评估值,而不是实际的分配值;它仅用于 PostgreSQL 查询计划器...
该参数只是一个评估值,而不是实际的分配值;它仅用于 PostgreSQL查询计划器判断索引的代价,越大的值越可能使用索引扫描,否则更可能使用表的顺序扫描。 effective_cache_size 默认值为 4 GB,保守估可以设置为是系统可用内存的 1/2。通常对于专用数据库服务器可以设置为系统总内存的 75%,可以根据特定的服务器工作负载...
ALTER COLUMN username[SET DATA] TYPE new_data_type; Q5. What is the Maximum size for a table in PostgreSQL? Even though PostgreSQL has unlimited database size for users, but it has a limit for maximum table size. The maximum table size is set to 32 TB. Note: This is very essentialPo...
*/ Size initBlockSize; /* initial block size */ Size maxBlockSize; /* maximum block size */ Size nextBlockSize; /* next block size to allocate */ Size allocChunkLimit; /* effective chunk size limit */ AllocBlock keeper; /* keep this block over resets */ /* freelist this context ...
| Type | Owner | Persistence | Access method | Size | Description---+---+---+---+---+---+---+---public | example_tbl | table | postgres | permanent | heap | 8192 bytes |public | pg_stat_statements | view | postgres | permanent | | 0 bytes...
Size initBlockSize;/*初始内存块的大小 initial block size */Size maxBlockSize;/*最大内存块大小 maximum block size */Size nextBlockSize;/*下一个要分配的内存块的大小 next block size to allocate */Size allocChunkLimit;/*分配内存片的尺寸阈值,该值在分配内存片时会用到 effective chunk size ...
ERROR: index row size 3720 exceeds maximum 2712 for index "idx_t_hash_1" HINT: Values larger than 1/3 of a buffer page cannot be indexed. Consider a function index of an MD5 hash of the value, or use full text indexing. postgres=# create index idx_t_hash_1 on t_hash using hash...
offMaximum data alignment: 8Database block size: 8192Blocks per segment of large relation: 131072WAL block size: 8192Bytes per WAL segment: 16777216Maximum length of identifiers: 64Maximum columns in an index: 32Maximum size of a TOAST chunk: 1996Size of a large-object chunk: 2048Date/time ...
[ALLOCSET_NUM_FREELISTS];/* free chunk lists *//* Allocation parameters for this context: */Size initBlockSize;/* initial block size */Size maxBlockSize;/* maximum block size */Size nextBlockSize;/* next block size to allocate */Size allocChunkLimit;/* effective chunk size limit */...