对Model进行查询、保存、删除操作时速度很慢，从Debug中看到很多query [ 2.0 版本 ]

对Model进行查询、保存、删除操作时速度很慢，从Debug中看到很多query

SELECT
    d.nspname AS table_schema,
    c.relname AS table_name,
    a.attname AS column_name,
    COALESCE(td.typname, tb.typname, t.typname) AS data_type,
    COALESCE(td.typtype, tb.typtype, t.typtype) AS type_type,
    a.attlen AS character_maximum_length,
    pg_catalog.col_description(c.oid, a.attnum) AS column_comment,
    a.atttypmod AS modifier,
    a.attnotnull = false AS is_nullable,
    CAST(pg_get_expr(ad.adbin, ad.adrelid) AS varchar) AS column_default,
    coalesce(pg_get_expr(ad.adbin, ad.adrelid) ~ 'nextval',false) AS is_autoinc,
    CASE WHEN COALESCE(td.typtype, tb.typtype, t.typtype) = 'e'::char
        THEN array_to_string((SELECT array_agg(enumlabel) FROM pg_enum WHERE enumtypid = COALESCE(td.oid, tb.oid, a.atttypid))::varchar[], ',')
        ELSE NULL
    END AS enum_values,
    CASE atttypid
         WHEN 21 /*int2*/ THEN 16
         WHEN 23 /*int4*/ THEN 32
         WHEN 20 /*int8*/ THEN 64
         WHEN 1700 /*numeric*/ THEN
              CASE WHEN atttypmod = -1
               THEN null
               ELSE ((atttypmod - 4) >> 16) & 65535
               END
         WHEN 700 /*float4*/ THEN 24 /*FLT_MANT_DIG*/
         WHEN 701 /*float8*/ THEN 53 /*DBL_MANT_DIG*/
         ELSE null
      END   AS numeric_precision,
      CASE
        WHEN atttypid IN (21, 23, 20) THEN 0
        WHEN atttypid IN (1700) THEN
        CASE
            WHEN atttypmod = -1 THEN null
            ELSE (atttypmod - 4) & 65535
        END
           ELSE null
      END AS numeric_scale,
    CAST(
             information_schema._pg_char_max_length(information_schema._pg_truetypid(a, t), information_schema._pg_truetypmod(a, t))
             AS numeric
    ) AS size,
    a.attnum = any (ct.conkey) as is_pkey,
    COALESCE(NULLIF(a.attndims, 0), NULLIF(t.typndims, 0), (t.typcategory='A')::int) AS dimension
FROM
    pg_class c
    LEFT JOIN pg_attribute a ON a.attrelid = c.oid
    LEFT JOIN pg_attrdef ad ON a.attrelid = ad.adrelid AND a.attnum = ad.adnum
    LEFT JOIN pg_type t ON a.atttypid = t.oid
    LEFT JOIN pg_type tb ON (a.attndims > 0 OR t.typcategory='A') AND t.typelem > 0 AND t.typelem = tb.oid OR t.typbasetype > 0 AND t.typbasetype = tb.oid
    LEFT JOIN pg_type td ON t.typndims > 0 AND t.typbasetype > 0 AND tb.typelem = td.oid
    LEFT JOIN pg_namespace d ON d.oid = c.relnamespace
    LEFT JOIN pg_constraint ct ON ct.conrelid = c.oid AND ct.contype = 'p'
WHERE
    a.attnum > 0 AND t.typname != ''
    AND c.relname = 'current_user'
    AND d.nspname = 'public'
ORDER BY
    a.attnum;

select
    ct.conname as constraint_name,
    a.attname as column_name,
    fc.relname as foreign_table_name,
    fns.nspname as foreign_table_schema,
    fa.attname as foreign_column_name
from
    (SELECT ct.conname, ct.conrelid, ct.confrelid, ct.conkey, ct.contype, ct.confkey, generate_subscripts(ct.conkey, 1) AS s
       FROM pg_constraint ct
    ) AS ct
    inner join pg_class c on c.oid=ct.conrelid
    inner join pg_namespace ns on c.relnamespace=ns.oid
    inner join pg_attribute a on a.attrelid=ct.conrelid and a.attnum = ct.conkey[ct.s]
    left join pg_class fc on fc.oid=ct.confrelid
    left join pg_namespace fns on fc.relnamespace=fns.oid
    left join pg_attribute fa on fa.attrelid=ct.confrelid and fa.attnum = ct.confkey[ct.s]
where
    ct.contype='f'
    and c.relname='current_user'
    and ns.nspname='public'
order by
    fns.nspname, fc.relname, a.attnum

'enableSchemaCache' => true //这里设置为true或false都试过了

诸如此类的sql query，仅对2个postgresql数据库建立事务、设置事务隔离性，对3张数据表用实体（ActiveRecord）执行2-4条数据的插入、删除，这一过程耗费了4秒时间；当我不使用model操作时，用纯sql command命令去执行，这些sql query减少了三分之二，速度非常快。请问如何设置关闭这些query的出现呢？