how long can a text field hold
Text (plain) varchar(16000)
<input class="js-text-full text-full form-text" data-drupal-selector="edit-field-article-text-plain-0-value" id="edit-field-article-text-plain-0-value" name="field_article_text_plain[0][value]" value="" size="60" maxlength="16000" placeholder="" type="text">
Text (plain, long) 基本没有长度限制
<textarea class="js-text-full text-full form-textarea resize-vertical" data-drupal-selector="edit-field-test-long-text-0-value" id="edit-field-test-long-text-0-value" name="field_test_long_text[0][value]" rows="5" cols="60" placeholder=""></textarea>