Normalized redux structure example (see https://stackoverflow.com/a/37266130/8602065)

Item.jsx

import React from 'react'
import { connect } from 'react-redux'

/**
 * Item Component
 */

const Item  = ({ item }) => (
  <li className="item">
    <div>
      <span className="item__name">{item.name}</span>
      <span className="item__type">{item.type}</span>
    </div>
    <div className="item__description">{item.description}</div>
  </li>
)

Item.propTypes = {
  itemId: PropTypes.string.isRequired, // used once in mapStateToPropsFactory
  item: PropTypes.object.isRequired,
}

// provides memoization for component instance based on initialOwnProps
const mapStateToPropsFactory = (initialState, initialOwnProps) =>
  (state) => ({
    item: state.items[initialOwnProps.itemId]
  })

export default connect(mapStateToPropsFactory)(ItemList)

ItemsReducer.js

import actions from 'actions/ItemActionCreators'

/**
 * Reducer (partial)
 */

const initialState = {
  items: {}, // normalized data of shape { id1: {…}, id2, {…}, …}
  itemIds: [], // keys of normalized data [id1, id2, …]
}

// waaay faster than _.omit, see:
// https://github.com/FormidableLabs/victory/issues/956#issuecomment-377567239
const omit = (items, itemId ) => {
  const { [itemId]: _omit, ...nextItems } = items
  return nextItems
}

const handlers = {
  /* Item list populator */
  [actions.GET_ITEMS_RECEIVE]: (state, { items }) =>
    ({...state,
      items: action.items,
      itemIds: Object.keys(action.items),
    }),

  /* Item CRUD operations */
  [actions.CREATE_ITEM_RECEIVE]: (state, { item }) =>
    ({...state,
      items: { ...state.items, [item.id]: item },
    }),
  [actions.UPDATE_ITEM_RECEIVE]: (state, { item }) =>
    ({...state,
      items: { ...state.items, [item.id]: item },
    }),
  [actions.DELETE_ITEM_RECEIVE]: (state, { item }) => {
    const nextItems = omit(state.items, item.id)

    return {...state,
      items: nextItems,
      itemIds: Object.keys(nextItems),
    }
  },
}

export default (reducer) =>
  (state = initialState, action) =>
    reducer(handlers, state, action)

List.jsx

import React from 'react'
import { connect } from 'react-redux'
import { compose } from 'redux'

import Item from 'components/Item'

/**
 * List Component
 */

const ItemList = ({ itemIds }) => (
  <ol className="item-list">
    {itemIds.map((id) => (
      <Item key={id} itemId={id} />
    ))}
  </ol>
)

ItemList.propTypes = {
  itemIds: PropTypes.arrayOf(PropTypes.string).isRequired,
}

const mapStateToProps = (state) => ({
  itemIds: state.itemIds,
})

export default compose(
  connect(mapStateToProps),
  React.memo,
)(ItemList)