gpdb memory control

• 1 TODO VMem
• 2 Resource Group Control
  • 2.1 Bypass
  • 2.2 Fixed Mem
  • 2.3 Memory Limit

TODO 1 VMem

2 Resource Group Control

• ResourceGroupGetQueryMemoryLimit(void) 用于获取内存限制的绝对大小 （非百分比）

2.1 Bypass

• 绕开资源限制模式

• Enabled when:

  • gp_resource_group_bypass is true: guc_gp.c

    {
        {"gp_resource_group_bypass", PGC_USERSET, RESOURCES,
            gettext_noop("If the value is true, the query in this session will not be limited by resource group."),
            NULL
        },
        &gp_resource_group_bypass,
        false,
        check_gp_resource_group_bypass, NULL, NULL
    }
    

  • Or command is one of:

    • SET
    • RESET
    • SHOW

2.2 Fixed Mem

固定内存大小

if (gp_resgroup_memory_query_fixed_mem)
        return (uint64) gp_resgroup_memory_query_fixed_mem * 1024L;

2.3 Memory Limit

queryMem = (uint64)(resgLimit *1024L *1024L / caps->concurrency);