*
   * <p>In contrast, the maps returned by {@code columnMap().get()} have the same behavior as those
   * returned by {@link #column}. Those maps may support {@code setValue()}, {@code put()}, and
   * {@code putAll()}.
   *
   * @return a map view from each column key to a secondary map from row keys to values
   */
  Map<C, Map<R, V>> columnMap();

  /**

/**
 * Implementation of {@link Table} using linked hash tables. This guarantees predictable iteration
 * order of the various views.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *

/**
 * Implementation of {@link Table} using linked hash tables. This guarantees predictable iteration
 * order of the various views.
 *
 * <p>The views returned by {@link #column}, {@link #columnKeySet()}, and {@link #columnMap()} have
 * iterators that don't support {@code remove()}. Otherwise, all optional operations are supported.
 * Null row keys, columns keys, and values are not supported.
 *

      table.put(1, "foo", 'a');
      table.put(1, "bar", 'b');
      table.put(3, "foo", 'c');
      return table.columnMap();
    }

    @Override
    protected Map<String, Map<Integer, Character>> makeEmptyMap() {
      return makeTable().columnMap();
    }
  }

      assertEquals(
          ImmutableMap.of(
              1, ImmutableMap.of('a', "foo", 'b', "bar"), 2, ImmutableMap.of('a', "baz")),
          testInstance.columnMap());
    }
  }

  public void testContains() {
    for (ImmutableTable<Character, Integer, String> testInstance : getTestInstances()) {
      assertTrue(testInstance.contains('a', 1));

        return map(transformValues(delegate().rowMap(), m -> map(m, mutex)), mutex);
      }
    }

    @Override
    public Map<C, Map<R, V>> columnMap() {
      synchronized (mutex) {
        return map(transformValues(delegate().columnMap(), m -> map(m, mutex)), mutex);
      }
    }

    @Override
    public int hashCode() {
      synchronized (mutex) {

        return map(transformValues(delegate().rowMap(), m -> map(m, mutex)), mutex);
      }
    }

    @Override
    public Map<C, Map<R, V>> columnMap() {
      synchronized (mutex) {
        return map(transformValues(delegate().columnMap(), m -> map(m, mutex)), mutex);
      }
    }

    @Override
    public int hashCode() {
      synchronized (mutex) {

entiende que la base de datos proporcionará el `id` y *define la columna como un `INTEGER` no nulo* en el esquema de la base de datos. Consulta la <a href="https://sqlmodel.tiangolo.com/tutorial/create-db-and-table/#primary-key-id" class="external-link" target="_blank">documentación de SQLModel sobre claves primarias</a> para más detalles.

* `Field(index=True)` le dice a SQLModel que debe crear un **índice SQL** para esta columna, lo que permitirá búsquedas más rápidas en la base de datos cuando...

- Parquet API supports columnar compression for  using GZIP, Snappy, LZ4. Whole object compression is not supported for Parquet objects.
- Server-side encryption - The Select API supports querying objects that are protected with server-side encryption.

## Ejecución de dependencias con `yield` { #execution-of-dependencies-with-yield }

La secuencia de ejecución es más o menos como este diagrama. El tiempo fluye de arriba a abajo. Y cada columna es una de las partes que interactúa o ejecuta código.

```mermaid
sequenceDiagram

participant client as Client
participant handler as Exception handler
participant dep as Dep with yield