Gatsby warning on build "query takes too long"

I am building a static website with Gatsby and Netlify CMS. The website is hosted on Netlify as well. I have a blog section and I generate a page per article from a markdown file. I have the following warning during build "query takes too long" for every article page I generate. The site builds eventually but the build time gets longer and longer the more pages I am generating so I'm afraid it will become too long when I start having too many articles in my site.

I am generating a page for each markdown file that is being created by netlify CMS.

Would you mind looking and the code I have in the gatsby-node file and the query I am using in my blog template file to see if I'm doing anything wrong that would explain the build time warning message ?

Thanks

Here is my development environment

  npmPackages:
    gatsby: ^2.26.1 => 2.26.1
    gatsby-image: ^2.10.0 => 2.10.0
    gatsby-plugin-netlify-cms: ^4.8.0 => 4.8.0
    gatsby-plugin-react-helmet: ^3.8.0 => 3.8.0
    gatsby-plugin-sharp: ^2.13.0 => 2.13.0
    gatsby-plugin-styled-components: ^3.9.0 => 3.9.0
    gatsby-remark-images: ^3.10.0 => 3.10.0
    gatsby-remark-prismjs: ^3.12.0 => 3.12.0
    gatsby-source-filesystem: ^2.9.1 => 2.9.1
    gatsby-transformer-remark: ^2.15.0 => 2.15.0
    gatsby-transformer-sharp: ^2.11.0 => 2.11.0
  npmGlobalPackages:
    gatsby-cli: 2.18.0

here is the code I've got in the gatsby-node file to generate my posts pages

exports.createPages = async ({ actions, graphql, reporter }) => {
  const { createPage } = actions

  const blogPostTemplate = require.resolve(`./src/templates/blog-post.js`)

  const categoryPageTemplate = require.resolve(
    `./src/templates/category-page.js`
  )
  const uncategorizedPageTemplate = require.resolve(
    `./src/templates/uncategorized.js`
  )
  const _ = require("lodash")

  const result = await graphql(`
    {
      posts: allMarkdownRemark(
        sort: { fields: [frontmatter___date], order: DESC }
      ) {
        edges {
          node {
            id
            frontmatter {
              categories
            }
            fields {
              slug
            }
          }
        }
      }
      categoriesGroup: allMarkdownRemark {
        group(field: frontmatter___categories) {
          fieldValue
        }
      }
    }
  `)
  // Handle errors
  if (result.errors) {
    reporter.panicOnBuild(`Error while running GraphQL query.`)
    return
  }

  const posts = result.data.posts.edges
  const categories = result.data.categoriesGroup.group

  posts.forEach(({ node }, index) => {
    const nextPostId = index === 0 ? null : posts[index - 1].node.id
    const previousPostId =
      index === posts.length - 1 ? null : posts[index + 1].node.id

    createPage({
      path: `blog${node.fields.slug}`,
      component: blogPostTemplate,
      context: {
        // additional data can be passed via context
        id: node.id,
        index,
        nextPostId
        previousPostId
      },
    })
  })
}

const { createFilePath } = require(`gatsby-source-filesystem`)

exports.onCreateNode = ({ node, actions, getNode }) => {
  const { createNodeField } = actions

  if (node.internal.type === `MarkdownRemark`) {
    const value = createFilePath({
      node,
      getNode,
    })

    createNodeField({
      node,
      name: `slug`,
      value,
    })
  }
}

and here is the query I've got in my blog-post template file to get the post with the id from the pageContext:

export const pageQuery = graphql`
  query($id: String!, $previousPostId: String, $nextPostId: String) {
    markdownRemark(id: { eq: $id }) {
      id
      html
      frontmatter {
        featuredImage {
          childImageSharp {
            fluid(maxWidth: 1600) {
              ...GatsbyImageSharpFluid_withWebp_tracedSVG
            }
          }
        }
        title
        description
        date(formatString: "MMMM DD, YYYY")
        categories
      }
    }
    previous: markdownRemark(id: { eq: $previousPostId }) {
      frontmatter {
        title
      }
      fields {
        slug
      }
    }
    next: markdownRemark(id: { eq: $nextPostId }) {
      frontmatter {
        title
      }
      fields {
        slug
      }
    }
  }
`